I'm 99% certain they're m10 x 25, same as the ones that hold the front crossmember to the body, beside the bumper iron bolts, and available from Heritage.
You are right, I found them on the ETKA thing Seem remarkably short for the job they do! Got that ready to go
Re them seemingly short... Well, if you think about it, a bolt really only needs to protrude 1.5 threads past a nut in standard engineering principles. And a typical m10 captive nut will be not even 10mm high, plus shall we say 5mm for the axle mount, and the section of floor the captive nut is welded to... So it's actually longer than it needs to be! *disclaimer* I take no responsibility if your axle falls off due to insufficient thread engagement!
Bit spendy (actually still less than VW price) but I used these. https://nutsandbolts.co.uk/index.ph...1-Metric-10.9-Grade-Geomet-500-Fully-Threaded The flange is very slightly smaller than standard but still has plenty of engagement, and you get a construction grade anti corrosion coating. https://www.diva-portal.org/smash/get/diva2:441388/FULLTEXT01.pdf page 30 and 31 have the pictures if you're interested
Could also go really fancy, https://www.accu.co.uk/en/full-thread-hexagon-bolts/270650-SEBF-M8-25-BUMAX109 Bumax 109 are Stainless bolts with the same tensile strength as 10.9 carbon steel, again very expensive but great if you want to attract smug comments about "ooo you shoudn't be using stainless there"
I did consider the Geomet ones. They are cheaper on eBay but I still baulked at the price. I went for the usual bright zinc from Westfield Fasteners whose prices are good and they don't screw you over on postage. I probably would have sprung for those stainless ones though, had I known about them.......next time
Yeah I old found out about them after buying all mine in Geomet but oh well. XCP rust block is really really good on bolts and things, I used S50 in cavities and XCP on bolts, leaves a slightly yellow film
I would not use stainless steel bolts on cars, they tend to gall and shear when you try to remove ! Use factory zinc passivated fasteners and you’ll be ok for another 2 decades or so !
FAIL! I can categorically state that the proportioning valve is not repairable/restorable. I got so far but the ultimate problem was that the rubber skirts on the piston had either swollen or lost their shape too badly to move freely inside the aluminium tube. I tried polishing out the inside of the tube but by the time I had fitted/refitted the piston the rubbers became more and more unusable. I think the reason there is no rebuild kit available is because the rubber skirts are crimped in and would be impossible to replace. Anyway, at least we all know what they look like inside and how they work, complicated bits for sure. And, I have a very nice steam punk paper weight I had forgotten how this thread started so had to go back and look
Does make me think that there must be a lot of cars on the road (relatively speaking) with valves that don't function properly, or at all.
Probably that’s why my powerful golf doesn’t feel like it’s got decent brakes ! The spring is rather sloppy on my brake bias valve too ! Might look into it myself !
As @Adamss24 say, use must use some sort of anti-galling anto-galvanic corrosion paste, something like Durlac green. With that you'll have no problems
