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SeanBZA
HumbleMechanic
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Comments by "SeanBZA" (@SeanBZA) on "HumbleMechanic" channel.

The tool bag is very good though for the car tools, which are very often the thing that gets you out of a bind. Also useful when you are at home or out doing DIY, as it can hold a lot of tools for small jobs. Well worth using, saving you from either not having a screwdriver or pliers on the road, or to carry stuff when at home.
53
They have a steel multipart mould that they blow polystyrene foam into to make the pattern for the block. This pattern is a complete head, fully detailed, so that when sand filled you simply take it and pour in the liquid aluminium and it burns the styrene away so you do not lose fine detail. That allows you to make thousands of patterns and not have any major wear on the master mould, and also the fine detail that you otherwise could not make in a pattern, like straight sides and undercuts, along with complex internal shapes, is easy, as the styrene parts are easy to work with, rigid and detailed. Might be a half dozen styrene parts finally into the sand, but one assembly, and there is no danger of crumbling blocking parts. Just glue them together with a drop of wood glue on the bonds, and fill with your casting sand, and cure the sand before pouring. Instead of lost wax this is a lost mandrel process, and the detail is fine enough that the actual polystyrene beads detail is impressed into the casting. You can get a really thin wall casting out of this, yet not have many failures due to blow through or incomplete pouring.
18
Funny enough by me last time I was looking to change VW CV boots the cost difference between getting just the boot and the clips was only around $3 less than buying the complete CV joint itself, and as a bonus you get a new CV, grease, new nut and about a half hour saved per side. Just undid the nut, lifted the car, took wheel off, then undid the ball joint, tapped the CV loose from hub, popped it out and tapped it off the shaft, then new ready greased CV went on, and 5 minutes later I had it in the hub. Old joint was just scrap then.
8
@aygwm There is, when the belt breaks the engine life is over.......
5
Most of those seals push in, so you remove the casting and press the old ones out, and the new one in. I would say that the cams are assembled using a jig that holds them all in alignment, and the cams and head are heated up to around 150C in an oven, while the shaft is in a liquid nitrogen or dry ice chamber, and then the shaft is aligned with the top casting and pressed into position fast, so that the cams shrink onto the shaft. Not easy to fix, but saves a lot of weight, in not needing any bolts in the upper head, and no chance for misalignment while boring out the bearing holes, though you will need to have very precise control of clearances.
5
@HumbleMechanic I can always do with a few more of them, they come in real handy. But shipping is a bit of an issue from USA to me......
4
Worst pain is the heater core, followed by the blend doors, because the entire dash has to come out. While you are there might as well also replace AC evaporator and fan motor, because by now both are pretty close to knackered. While core is cheap, along with the blend door foam, the labour to change them is not, and you run the risk of breaking any one of hundreds of little plastic clips that are now brittle, giving you rattles. When taking apart silicone spray is your friend, lots of it as you go for the clips, so they are at least able to slip off easier. Then replace all foam again, and add more dampening pads as well inside, as the originals are likely now well sad and crumbling. The good thing is that by me I can get the entire lot as pattern parts, seeing as VW has been consistently the number 1 or 2 seller in the country, with Toyota contending for the other spot, and the VW Golf and variants are well represented in the spare parts market, with pretty much all the vehicle being available as pattern, or OEM from all the local suppliers, who made them for VW to assemble. Standard joke you only cannot get the VIN plate as aftermarket.
4
Because it is faster, plus you get to upsell the customer on new hubs as well every few cycles, and break alloy rims as well for another upsell. Will also bet the place has a torque wrench, but it has never been calibrated, checked or even taken out of the box since new, unless they get somebody with a touch of knowledge as a customer, who will see it being used while they are present.
4
Bearing races are in general fine to intermingle, if they are from the same manufacturer and the same batch, as they will tend to be all ground to the exact same dimensions. You can even use different batches, but for close tolerance they might be slightly different due to the settings being slightly different between runs, but changing manufacturer is iffy, but still you will get good life out of them. Only with precision bearings will you have to use matched pairs, but if you are using them in a vehicle almost no bearing is in any way going to fall in this category till you are into parts like the AC compressor, and the crank and main bearings. Fun thing is that VW rear bearing is very commonly used on trailers, so to repack the light duty trailers it is a lot cheaper to go buy the aftermarket VW rear bearing kit instead of the trailer manufacturer kit, and use it instead. Normally the caps will not fit off the bat, so you need to either reuse the old one, or spend a bit of quality time with a hammer to make the new cap shrink to fit the diameter.
3
Seen a similar thing on a Ford 1.6 CVH engine, would start, but only run with throttle held near full, and not idle. was looking and wanted to check if there was actually oil in it, so pulled dipstick with engine running. Idle dropped to near normal, with still full throttle, and on removing oil filler, it dropped stone dead. We could have rebuilt it, but instead it was quicker to instead send it to Ford themselves, and get a complete new engine from them in return. Not cheaper, but the engine was needed urgently as otherwise there would be massive delays and lack of critical equipment. This engine was used to drive a hydraulic pump, and this in turn was a specialised vehicle that there were only a very few of, so a missing one was somewhat of a crisis. Not over revved, as they all had limiters on them ( though often bypassed, so we locked out the throttle plate range instead with a welder, to hold that limiting bolt firmly in place), best we could guess is somebody ran it without oil, or with low oil level, and cooked the bearings and rings, or had not checked coolant, and the engine had overheated. Same end result. Otherwise those engines were pretty robust and gave little issues. Those VW 2.0 TDI/TSI engines also are the power plant on a lot of fork lift trucks, where they live a very hard life, long idle times, frequent stop starts, hard running when cold, and generally just abused. Amazingly they do survive that quite well. Saw them often at plants, pop that cover and the VW logo is there, while the outside is quite a different logo.
3
Drive it for about 30km going for as many shifts up and down as you can, especially on hills and with varying speeds. That way the controller will learn the shifting pattern and timing of the new valving, which should fix a lot of those issues, and also bleed the solenoid circuits properly as well. Otherwise see if the VAG tool can set the controller to relearn, which is the same thing, just less fun.
3
Will fix itself within an hour of driving, after it is warmed up.
3
Still many thousands of those Citigolfs running on the roads here in South Africa, even though they are all getting a little old, but the aftermarket spares are still around, and you can get almost the entire vehicle as second source parts.
3
If VW just buy the front hub complete, and then the shock. will be quicker and easier. While you are there buy the steering boots, 2 CV boots and tie rod and ends, because they will all also very likely be less than willing to either come off, or worn well past happy.
2
There is a whole kit of the plastic parts for this, either aftermarket or from VW spares. Mostly easy to install, though you will benefit from a lot of rubber grease to help with the places where they go into the housings and where all the sliding parts go. My VW was sloppy, and the one plastic bush for the ball was out of stock, so replaced the rest, and then simply used a lot of cable ties and rubber grease to make the fit better.
2
Seen one Datsun Go, with around 100mm of spacers on it. Wheels are also skinny rubber on wide rims, and look like they will pop off at the first pothole, plus ultra low profile tyres. Figure the wheels and tyres, plus the spacers, cost more than the car, and do nothing to improve stability either.
2
Went to the dealership this week, they have changed things up a lot, hand sanitiser, wiping the vehicle down inside before they take it, wipes available all over, and then they wipe it down afterwards when you are collecting it.
2
Few minor chips in the gear teeth, so just how much fluff was on the magnet in the housing then.
2
That floor panel is easy to get as pattern, and simple enough to cut out the bad section, cut matching from the new one, and simply spot weld in place.
2
@HumbleMechanic You can at least look at getting used parts to rebuild, like the SRS stuff, off of one that perhaps got totalled in another way but did not have SRS activation.
2
That differential fluid change for one, and then a 10 minute road test with you showing how this performs.
2
Those bolts are called shoulder bolts, which are commonly used to make a slide or a bearing inner pivot. Around $2 each retail. Looks like they are 8mm by 50mm, a common enough size for them, and often used in machinery where you have sliding parts that need a precision guide, like in plastic moulding.
2
Just replace with the stock ones, it makes a massive difference in handling. Solves around half of your body roll just having new shocks and rubbers all round.
2
@skylinefever No, that I think was Toyota using models they traditionally did not offer in the US market, done under a different brand name.
2
You have to remember the one who bought it was used to ignoring all those lights in the centre display, yet another red warning and chime was just ignored, and it eventually, like the engine, went away.
2
Most good consumer protection laws will cover that, in that you had the issue while under warranty, had multiple visits to attempt to fix it, and now it is out of warranty oops expensive. Depends on where you are as to what they cover, but often just trying to run you out of warranty is not an excuse.
2
@tommorides8086 Well, sealed for the warranty life, but if you actually want to keep the vehicle past the warranty, you should change all the fluids. Only the plain mechanical boxes do not really need a fluid change, because that oil fill is good for at least 30 years in there, as it is running with little stress on it.
2
All those plastic parts though are soon available as cheaper pattern parts, simply because of that. Even the dealers buy them as well, especially for older vehicles.
2
Friend solved it on a Golf, got a VW remanufactured engine and put it in. All new seals, 2 year warranty and cheaper than stripping the engine down and replacing every seal, new bearings, doing the head and new rings. The one he got was a leftover engine from the production line for that model, basically never used.
2
Bolts are easy, plus the different lengths for steel versus alloy rims are hard to do in a stud form, either they stick out far, or are too short depending on the wheel type. Not much difference from each other, just that bolts at least have the wearing part easier to change, plus broken ones are, because the tension is now off them, are easy to remove, provided you have not left them on for ages to rust fast. Studs on the other hand are a PITA to change, especially when you have no clearance behind to remove them, and have to take a hub apart to do so. Smaller heads as well on them, so smaller diameter possible on the wheel boss, while still having enough strength and fatigue life to last.
2
Big nut ( M12) placed there with a fender washer will enable that home made press to get the bushing all the way in without needing it to be hammered and dented.
2
@markrobinson3868 Like he said, likely the sensors or the wires right by them, and they are cheap enough to buy and put in.
2
@christopherwitter9496 Yes it makes a big difference in fuel consumption, as the engine management will then run rich, so as not to have any chance of cylinder temperatures going too high and causing knock, and will also run on a very conservative advance map for the same reason, so your power will drop. IIRC your VR6 engine has 2 knock sensors, and they are not interchangeable, but aftermarket ones are cheap and easy to install.
2
@christopherwitter9496 One on the side near the front I think. Well hidden, but just look online for the sensors and you get them and the locations. Generally they do not fail, but the wiring or the connections for them do. You need to use some form of diagnostic though to check they are the fault, before replacing them.
2
Use non locking thread sealer, as it will keep the thread clean and tight, but will break loose with ease when you want to get it out. There is a white Yamaha marine one I use, which keeps the thread clean, even in salt water applications where it is submerged often. The aviation industry has a yellow one, which is ultra expensive, but which works really well. Used to use it by the bucket.
1
@HumbleMechanic Just how far do you have to lift up the front of a Golf to get the mounting holes for the starter to engage..... Till the wheels leave the ground is about it. But at least that starter is easy, only 4 bolts on the actual engine (one for a bracket, 3 for the starter/engine mount), and it comes out easy enough. Unlike certain others, where you land up taking half the engine and underside off to get to the last bolt, or have to take inlets or exhausts off to reach. While you are in there gets expensive, because you know half of those bolts and studs are going to be less than willing to come easily. Why yes I do have a lot of anti seize for when they go back, I will probably be the next one to remove them anyway, or at least will make life easier for the next one.
1
@HumbleMechanic Still have the coffee-o-matic, but it has only disposable cups, and no snacks to be seen. Was not going to chance the open canisters of sugar and tea they still have around, but as I do not take sugar no great loss. Water was boiling hot though, so the cups were sterile. Was still drinking the one cup 20 minutes later, it was too hot.
1
Garbage in garbage out. If the grounds are poor, or the sensor in the shifter is failing or corroded, then the ECU does not know gearshift position, or has unreliable info, so definitely will throw a wobbly. you would definitely need to have this done via a tool, and reading the inputs from the gearbox and engine.
1
By me the joints and boot are available as a part, the complete axle is very much an agents only part, and very much more expensive, so pretty much all the time just the boot or the CV is changed. Big difference in labour rates in the USA is why a new axle is the preferred option, as the cleaning costs you at least an hour more in labour.
1
Done mine, though having basically a Golf 1 makes it easier, just have to undo starter to get the new one in. Just have to do the transmission one to finish it, but they were not worn, just 18 year old rubber. Cheap as well, and work well enough being "second source", and funny enough the agents also use them as well.
1
Going to bet 6 bent inlet valves, and probably also 16 lifters will get changed, as they probably will show, like the ones from the oil fill, severe wear on the rollers. Friend had it occur twice, both times the day before the service, which was also to change said belt.
1
Could be worse, you could drop a nut in there, and not know if it went into the hole, or dropped on the floor......
1
Bearing was definitely done in by the shock installer. Those are cheap parts to replace with the strut, but of course most places will rather keep the extra $5 as profit instead, and recycle the old ones back so long as they are not in a million pieces when removed. Million pieces internally, but so long as the bits stay together until the vehicle leaves no problem. Just did mine beginning of the year, and while they were not as bad, steering was definitely better, plus I actually had working shocks. Did nothing for roll in cornering, but I nearly lost fillings the first time I went over a speed bump at what I was used to, and the suspension moved the vehicle up sharply, then down again as sharp.
1
Who says that was not the house.....
1
Going to guess the biggest improvement was the new catalytic converter, where you had the obstructions removed from the passages. My car I went for a branch, because the stock casting cracked, and no real improvement on power, but at least no exhaust noise increase either. But then, 1.4l golf is not exactly a power house anyway, but a nice reliable driver.
1
@Wolfpack310 My 1.4l NA is now no longer a teenager, and yes did get a rebuild head wise, to get rid of the usual smoke issues. Also replaced every seal while it was out, and also replaced clutch at the same time. 270 000km on it.
1
@Wolfpack310 AGY, basically the vanilla VW Golf engine, in over 30 million vehicles made in South Africa.
1
@Wolfpack310 Yes, the old iron block, still a common item, that you can actually buy from VW as a brand new crate engine, or get a factory recon from them as well.
1
How about fuel pump, just unclip the baffle, and put the pump in place of existing one.......
1
Probably lost by the squirrel that was thinking of taking up residence there while it was parked.
1
Charles, just had a 21 year old VAG coil finally pop, off my old VW Polo. $30 for the pattern part, 3 minutes talking nicely to it with a 10mm spanner, and away it went again.
1
Next to replace the entire brake system. Luck that is all still available, from the pedal to the drums.
1
Yup, had to change the pump, not because it was faulty, but because the fuel level sender wore out, and was erratic below a half tank.
1
@Dave-in-MD Reply yes, any cheaper it has no return, no warranty at all.
1
How about the VW Up engine, even if it is technically not a VW engine.
1
@skylinefever Toyota Aygo or Datsun GO, and also the Citroen and Peugoet versions. Yes not likely to have been sold in the USA, as they are small vehicles with small engines. You can park 2 of them in the parking space you need for the Mini Clubman.
1
@HumbleMechanic I found it, and another one, plus 2 10mm spanners. Now, to find that 13mm spanner, I know I had at least 5 of the darn things, but all I can find are 12mm sockets, and only some bolts fit.
1
Pretty much the most popular vehicle here in South Africa is a VW of some form, mostly the Golf, which had been produced in some form or the other for 40 years, and which is pretty much entirely available as aftermarket and performance parts.
1
If you skip OEM and go for aftermarket that bill would be a lot lower though. Especially in countries where VW is the most popular vehicle around, and you can get just about the entire vehicle in spare parts, without ever stepping into the dealership once, though you better still have the front badge, as that, along with the VIN plate, is OEM only.
1
@clayniemann2608 You also find that plaster and paint can hide a multitude of sins.
1
Saw one the other day. Looks very nice, though at first glances I was wondering which variant of the MB sportster it was, till I got close enough to see the model name. That massive centre stop light......
1
Small amounts no, but putting on spacers that put the rims outside the wheel arch and show a lot of tyre will lead to high forces on bearings that in general are designed for the load to be mostly symmetrical around the bearing. Higher wear, and higher loading of the bearing during driving, and of course potholes will cause extra wear. Use small amounts to correct for different rims not going to be any major problem.
1
Can of spray silicone oil works wonders to find rubber bushes with problems, though if you are replacing them hit the new parts with rubber grease first to get them in, and warm them up in boiling water as well to soften the bushes. As well the grease on the threads means that when you need to replace it again it will not be a solid ball of rust.
1
While I am in there, involved chiselling open a ceiling at 10PM, so as to get the buried junction box open, so that I could make a new cable change direction. Luckily I did have 100m of cable for the conduit already, and got that floor free of the old rubber insulated cable. Another involved removing nearly 20kg of old cable, inside the machine bowels, and replacing it with 100m plus of new, because I could not be bothered trying to trace where that spaghetti went, so took the original diagram and made the unit match it again. Whole load of mystery relays came out, including some tucked up in the wiring area itself, behind the steel cover, which in turn was covered with a whole host of pneumatic valving. Only used 4 packs of cable ties there.......
1
Done water pumps in under an hour, one even at the garage after driving into the town at sunset.
1
Going to bet they were unhappy with the rust on the firewall near the HVAC air inlet, and also under the cowl, as that is also a common place to have rust.
1
Not enough varnish to say long running with no oil changes, and likely it just was burning oil, and eventually burnt all of it. When he was pulling the top apart the cams and such did not look like they were running in crude, just regular "change at 20k instead of 15" sadness and cooked on deposits Just they did not bother with filling it when it got low, especially with the extra boost pumping oil vapour into the engine, and it all got burned, followed by the bearings being burned to the crank.
1
Yes it's a VW, it does break down. However fixing is cheaper and faster than with GM, and in general they only break down when stressed from towing all the GM vehicles to the shop. Reminds me, should really replace that knock sensor, the connector itself fell apart, so really should replace it instead of the wire holding the pieces together.
1
Easiest thing for the floor is to simply rent a buffer, and clean it using the rotary brush attachment, water and detergent in the mix tank, followed by a rinse, then simply use a commercial liquid polish to seal it, probably 3 coats applied with a flat mop. Will seal the concrete from spills and stains, and will at least keep the dust down, plus easy to patch as all you do is strip with polish stripper, wash, let dry and then apply another coat. Do every year as a maintenance task, and it will still allow you to have bare concrete look, but a little more resistant. Downside is if you want to do epoxy afterwards you will have to diamond grind off a millimetre more of the surface to get to bare substrate, so add an hour or two to the epoxy job.
1
Calcium based road salts to prevent ice forming above a specified temperature, which when it hits steel makes for a great cathodic rust cell all over the underside, and with all the pinholes in the coating from road debris this makes the underside rust like crazy. I live in a place which is the second rust capital of the planet, and here it is only salt spray, and vehicles do not rot out as bad as in the cold states of the USA. more because the local manufacturers long ago went and put in proper protection on the underside metal, and then put a decent paint coat on every part as well, so that there is very little bare unprotected steel around.
1
Likely the wide gaps and failing coil was the thing that killed the PCM, by subjecting it to high primary side voltages, above what it would get in a properly running engine. Says the owner did not maintain the vehicle properly, and sorry that you, and not the owner, were the one to pay for his short sightedness. Just remember that for the next one, where you get that, and say up front that this neglect can have damaged the PCM as well.
1
Documentation is great, because you will not remember what you did a year ago, but having it all written down is a big help when you get the same or similar problem again.
1
I did one day go to the scrapyard with around 50kg of old assorted nuts, bolts and screws, all old stuff. Little transparent thing is the flower holder from the New Beetle, which was part of the dashboard. I found an old ford distributor for my old ford, and gave it to the distributor rebuilders, as a core, because those CVH engine parts are getting a little long in the tooth now, and this one was a still reasonable one, complete and ready to go.
1
@DrewLSsix Funny enough where I am much cheaper buying VW parts than buying GM spares. Even though GM parts are mostly Daewoo, they are very much more expensive, as they are sold as if they are US made. VW hub assembly is under $40 here from a reliable second source, and includes every part. Good thing about GM is that here you just buy the equivalent Daewoo part, either genuine or pattern, and avoid what is left of the GM network, but always a week or two wait for parts is common.
1
@HumbleMechanic Grease the parts of the pin that go in the bushings as well before putting in, along with a bit inside the bushing. That way the lubricant is actually where it is needed, and not just on the surface, unlike the factory that put them in bone dry before the paint shop, and afterwards showed them a drop of lubricant is passing, leading to them wearing. Sagging door I have in the past used the car jack to gently bend up to be a better fit, was just sagging because cabrio and heavy doors but not worn pins. Soft body panels have moved with age, moving the hinges along with them.
1
Just need to add a fire extinguisher ( dry powder, and if possible a CO2 next to it as well) each side of the garage door, and another by the other entrances. That will at least give you some time if there is a fire, and your insurance rates will require it as well.
1
Would make a nice table, or a footstool. Did that with a roll of 0 gauge cable, seeing as I have a lifetime supply of it in the one roll.
1
Repairable though, those bearings are parts you can get.
1
Tip if you want to not drill into the tool boxes is VHB tape, it will pretty much hold better than the paint, and also gives a small amount of compliance in the joints. Will also stick to the wood nicely, just make sure both surfaces are clean, dry and oil and wax free.
1
@HumbleMechanic For you they are cheap, but for the rest of the world they are an expensive item, so I would want to keep it as good as possible, in line that in future i might want to repurpose it. Adjustable feet a good idea, and I would also apply the same surface protection to the underside, as that will at least keep the warping down if you live like I do in a climate where you have considerable humidity swings between seasons. Would also add a row of socket outlets underneath, along with a desk hole and cover each end, so that you can have things like cordless tool chargers and such neatly arranged, but with the power cords out of sight and clutter. A length of slotted conduit as well under the sockets to hold the cord excess, and then a box and switch above, so that you can turn the whole lot off with a single switch at night, reducing the fire risk from dodgy wall warts. If going the whole hog would also add a length of LED strip under the front, along with a switched power supply, so that you have easy lighting when down on the floor plugging things in, or fetching stuff from the shelves.
1
$8k for a new engine, thankful a new engine for a VW golf from VW is under $2k by me. Biggest cost was the "while we are here" things though, like a new clutch, new carburettor and such.
1
Depends, are any of the hoses still original, and have you always run antifreeze in it. If the hoses are all new, and the vehicle has been run with antifreeze to manufacturer spec for change, you probably are fine, though you will find the oil cooler is no longer available as genuine VW part, though there are aftermarket ones that are made by the same OEM's who did them for VW, which are as good as original.
1
@HumbleMechanic Just be thankful that you can get those plastic parts as aftermarket as well, as there is a large volume of VW spares around, and thus the OEM parts in general are cheaper. Unlike certain 2 letter US brands where they think that they should charge you as if all parts were made in the USA in dollars, but buy them in Won at a very low price, and make a massive mark up on them instead. If you need 2 front struts and an engine mount, and they cost more than the car, while for VW and even BMW even from the agents they are affordable.
1
VW U We don't believe in anything but quantity....... Saved 300g per vehicle, and is guaranteed to make a generation of mechanics rich as they age. But there are no new designs where large parts of the engine, drivetrain and body are not plastic parts. Cheaper to make those moulds with a hundred individual sections that have hydraulics to move them in the machine per cycle, than to stamp out steel panels where you need a half dozen different dies and presses to get them to that shape, and still need to do extra processing on them as well. The plastic dies also last longer in use, many tens of thousands of parts between needing to overhaul them, as opposed to the metal press dies where they run a few thousand parts before they need to fully rebuild the die. Also can handle thinner walls in the plastic than what you can do with molten aluminium alloy, and no need to have complex sand castings for each part, made from up to a hundred patterns, burn out fillers and cores.
1
I will say though they are very strong and safe vehicles. Where i used to live one got t boned by a Fiat Uno, which was skipping a red light, and hit the Porsche (less than a week old as well, under 200km on the clock) on the driver door, and punted it 80m down the other road. Uno was basically crushed back to the firewall, and the cabin itself was compressed and buckled as well. Porsche though, all 14 airbags deployed, car was bent front and rear and looked like a banana, but the driver just had powder burns, and a bruise from the side impact airbags, and was otherwise fine. But the thing was that, despite being hit on the driver's door, and having a massive dent in the door, the cabin was still intact, only slightly warped, and that door both was still openable, albeit with bent metal impeding you, but also still would close and latch properly again. Uno driver had to be cut out of the vehicle. Both written off. Uno driver left in ambulance with police escort, and Porsche driver left with a friend who picked them up. both left on lowbeds, one because there was no way it would tow, and the other because all wheel drive, and towing companies not wanting to get the bill for the extra damages from incorrect tow.
1
SAE tooling for that banjo bolt because they are still an imperial thread, and you will never be able to change that, as it is a 1/4 inch pipe fitting. Just remember your caliper bolts, brake fitting threads and all hydraulic fittings are a metric equivalent fitting, because the old stuff was changed to nearest size. 2.5 and 4mm hex keys, very common in industrial machinery, though I will tell you that, if they do get seized fast, the easiest way to get them out is to have a few of those ultra cheap 30 piece 1/4in hex driver sets, and look for the Torx bit that will just not fit in, and tap it into the damaged hex head, so you can turn it out. Will get it out, and if you do not have a replacement capscrew, you can put it back in again with it, and wriggle it with a pair of pliers to get the bit out, making it into a Torx head. Done that very often, because you might need that machine to run right there and then, and driving to get a new one, adding an extra hour of breakdown time, is often not an option. Make a note to keep that size as spare parts, for the next visit. I go through a lot of those size, M4 and M5, as they are a common thread, and you find often the stainless steel will gall fast to the aluminium parts if you do not use a thread sealer on them, especially if they get hot. I also have the thread repair kits for those sizes in various lengths, and the extractors for the broken screws, though you really burn through cobalt drill bits doing that, especially for the 8.8 high strength variant, and the left hand thread version drill bits are stupid expensive, even in plain HSS. Ridgid do make a really nice extractor set, but sadly the lifetime warranty does not apply by me, so I have had to buy some replacement sets along the way, because I always break the smaller sizes.
1