Brake disc is too thick for calliper

[Aaronrichie]

I have a 1986 t25 1.9l petrol van. My front wheel bearing went and in the process severely damaged the outer piece of the hub. I bought a replacement hub and brake disc assembly from just kampers only to discover the brake disc is about 4mm too thick and so doesn’t allow enough room for the pads to slot in place. I have been searching for quite some time now and cannot seem to find a disc that matches the original disc at a thickness of 9mm… they all seem to be 13mm. This is very urgent as I’m doing this as a roadside repair. I’m 21 and quite inexperienced with this sort of thing, any advice would be much appreciated thanks!

[multisi]

What type of calipers do you have? Are they the early basic type or the later sliding type. You may have have the cross over year model van with an early style front brake set up and you have ordered the late type brake disc. I just looked at my genuine vw late discs fitted last year and they are the thicker measurement.

[slowcoach]

Getting a photo up on here of your calipers will help get you on track

[Aaronrichie]

I have the girling callipers. I have actually bought 2 brake discs at this point… the first one being featured in t25s from ‘79 - ‘86 and the second from ‘86 - ‘92. The first one was completely wrong and the second is a good fit except for the calliper and brake pad fitting as the disc is too thick. I can’t take a photo at the moment as the van is stuck at the side of the road 40 mins from my house :/

[multisi]

You may need to push the piston back in to fit the pads.

[Aaronrichie]

I’m not sure if it’s possible cause I was trying that today by attempting to lever the pads further apart but it doesn’t seem like that gap can be increased… I must be doing something wrong

[maxstu]

13mm is the normal thickness l believe.

Pop the cap off brake fluid reservoir, place a clothes below the reservoir to catch overspill and try levering apart the pads again.

[mioba]

measure the thickness of the old disk.

have you made sure piston is fully back - open brake fluid tank (lots of rags around) use a piston rewind tool.

Dont get BF on anything - its nasty stuff.

[mioba]

and if you are inexperienced (ok we all start somewhere) dont guess it. Maybe google a mobile mechanic to help you out.
BW are best for parts in my opinion

[Aaronrichie]

Cheers guys, I’ll give that a go tomorrow. Am I likely to spill the brake fluid? Should I have some fluid to top it up with afterwards? Also I’ve measured the old disc to be 9mm thick whereas this new one is 13mm.

[Aaronrichie]

I’m trying to do it myself as I restore classic cars for a living and so I’m keen to learn!

[mioba]

If you retract piston you should not force it out of the reservoir.

A turkey baster is good to remove some if you not sure.

You wont lose any unless it spills everywhere.

Maybe a good time to change BF - or shall we leave it for now....

ps hope you are changing other disk too!!

[maxstu]

Cheers guys, I’ll give that a go tomorrow. Am I likely to spill the brake fluid? Should I have some fluid to top it up with afterwards? Also I’ve measured the old disc to be 9mm thick whereas this new one is 13mm.

Depends how much fluid is in reservoir.

Start again by cleaning off all road grime from pistons and protective seals with brake cleaner and a bristle brush, or your partner's current toothbrush, using brake cleaner.

The caliper pistons should go back flush with the walls of the caliper. Use a G clamp or similar to pinch it back to maximum opening.

[Aaronrichie]

Trying to do the bare minimum to get it back on the road so that I can drive it home, not ideal doing this stuff at the side of the road! I’ll worry about changing brake fluid and the disc on the other side after I’ve got it home safely. Okay thanks got a good idea of what I’m doing now, I’ll head down in the morning and hopefully be driving it home!

[Aaronrichie]

So I was able to get the calliper onto the new disc and I replaced the pads too… there’s now an occasional squeaking noise coming from the wheel on that side. Would I be silly to drive it home? Maybe if I put the old pads back on I won’t have this issue? Please help!