I know this has been done to death so I apologise but I am about to spend lots of money again and I want to get it right. Rear drums to discs, checklist of what I need. Anything missed? Mk2 GTi stub axles. Mk2 GTi discs. 226mm x 10mm Mk2 GTi caliper carriers Mk4 calipers Mk4 brake hoses Mk4 brake pads Proportioning valve This lot should do it - correct me if I am wrong. https://www.ebay.co.uk/itm/290311053996 https://www.ebay.co.uk/itm/303440421105 https://www.ebay.co.uk/itm/164153391843 https://www.ebay.co.uk/itm/292982713691 https://www.ebay.co.uk/itm/201239544770 https://www.ebay.co.uk/itm/151616362745
Hoses, I'm pretty sure it's not mk4 ones. Passat, possibly? Have you the bracket for the valve? Disk backing plates? The hard lines are quite a bit different too. Have you a way of making new flares, and bending the pipe? Please please please don't use copper, use CuproNickel/Kunifer. Pads, mk2 ones are fine. Bearings, seals, nuts, pins, grease for the discs? IMHO, it makes more sense to try and get a complete GTI axle... If nothing else, you can build it up off the car. Plus it will have the integrated Anti Roll bar, unlike every NON GTI axle.
Thanks Tristan. I'm going to use an after market proportioning valve mounted under the bonnet. I will buy/borrow a flaring tool. Not going to use backing plates, I've always binned the from other cars. Bearings etc come with the stub axles in the kit above. Have you tried findings complete rear axle lately? Like the proverbial rocking horse........... The car handles great so I'm not too fussed about a rear ARB.
Handbrake cables are different drum to disc too Phil, also, did you keep the stub axles off mk3 gti? Can use those, plus the bracket to hold the caliper hose/hard line that clips on trailing arm, I've got a pair if need those mate. My mk2 driver had the rear proportion valve on it already , I do have some valves off of a focus that fit in line, to reduce rear pressure which I was planning to use before found mine didn't require them. And yes, it's passat hoses that go hardline to mk4 calipers, I used them on my caddy, think it was a 99 or 00 plate I got them off, or can buy braided conversion lines from Hel or goodridge etc. Could use 9n polo stub axles with 6n2 hubs and bearings which are more modern than mk2/3 style, but would need a plate to mount calipers between the stub/arm, I made my plates from an ibiza/polo/fabia rear beam by hacksaw and grinder. I paid about 30 for rear beam, complete with calipers and got a deal on 6n2 discs and hubs/bearings, 50 from memory.
Thanks Dave. No, sold MK3 rear beam complete. An adjustable valve is only £35 so about a third of the price of a VW one with a bracket. Where does the Passat line run from and too?
https://www.ebay.co.uk/itm/Brake-Ho...2349624.m46890.l49286&mkrid=710-127635-2958-0 That's the style hose, it goes to caliper from the rear arm near shock mount. I can get pic of mine and I can post you ghost brackets, I bought the ones from creationsmotorsport but they didn't fit well and were basically an L bracket with a 15mm hole in it. You need gti handbrake cables, for discs not drums, post 88 for yours obviously.
That's my bought bracket with a mk4 caliper adaptor hose, but passat one is same position. Be aware some passat hoses don't have the banjo bolt with them, and there is a similar hose that is beam to arm, but has 2 male ends like the mk2. The mk3 bracket may position the hose slightly further back
That hose looks very similar to the one in the eBay link I put above? Do the brackets need to be welded on to the beam? Not a problem if they do. Funnily enough a GTi rear beam has just popped up on eBay. Its only £30 but another £45 on fuel to get it plus it looks like it would need most parts replacing anyway so I'm not convinced its worth it.
The passat hose is just the flexi bit, those in your link are hard lines too, similar to the 9n3 polo/ibiza/fabia platform and are probably steel so bending is tricky. The passat one will fit onto your original pipe to wheel cylinder, or may have to shorten slightly or adjust the routing. Bracket can be welded, screwed or rivot, the actual arm is not that thick so easy to drill. Aye, factoring fuel in and what is actually useful off of the beam without replacing it is an eye opener. I've been lucky finding stuff locally recently. Oh, don't forget 4 caliper carrier bolts, they are ht m10x1.25 x30. Link below has part number, so try vw directly to compare price. https://www.ebay.co.uk/itm/2x-Genui...2349624.m46890.l49286&mkrid=710-127635-2958-0
MK3 golf also good donor for stubs and caliper carriers, plus the calipers then they fit right up with standard mk2 flexi without having to use custom brake hoses or sourcing passat ones. not like mk4 are actually any better than mk3 they can still corrode and more chance of bleed nipple corroding. only real advantage is they're a bit lighter for backing plates mk2/3 if going mk2/3 stub axles, handbrake cables use mk2 gti matched to the age of the car. if you gety a really good flare tool you can cut the originals and re-flare, the hardlines are held with a spring metal bracket which is shoved into the end of the beam again mk2 or mk3 will do note the 1.1-1.3 beams are made of thinner steel than the 1.6-1.8 as well as having no roll bar like the gti versions so a good plan to get a complete donor beam to rebuild off the car at your leisure. try all the usual breakers and try to get one with bias valve still attached. not all mk3 gti have them. can go aftermarket like you say mind
the brackets bolt on for mk2 and mk3. the pivot bracket is specific to bias type so make sure that is included. the mk2 beam bracket bolts on, the mk3 its welded on the inside but is always there even on non-bias cars
The thing with the aftermarket, in line bias valve, is that it doesn't compensate for suspension movement like the oem one. Which reduces the rear braking effort more and more, as the rear gets lighter. Such as in hard braking.
aye I'd always prefer original. they also are clever enough to see when a brake circuit has failed and send maximum brake force to the remaining rear wheel
Interesting, I didn't know it did that. Mind you, after 30+ years of rust, dirt and gunk I'm doubtful it still would.
Yes, they have to, I think it was actually mandatory on all vehicles of that era. Makes sense too. I did a trackday once in my mk2, with the stock load sensing valve adjusted too much to the rear, and under hard braking i nearly spun the car several times.
Right, delving deeper it seems the Mk4 calipers are for 232mm discs and the Mk2 discs are 226mm. Does this matter??
Is it carriers that alter the 'throw' for diameter? Like the front ones do, so use mk2/3 rear carriers with mk4 calipers?
I've only retro fitted polo 6n2 gti or the 9n/ibiza setups on cars to be honest, well, plus a 256mm rear from a leon cupra on the golf. So was rambling my thoughts really @Tristan were the pads nearer the disc edge or overhang? It's only a couple of mm radial difference overall.
