VW T4 Forum - VW T5 Forum banner

1 - 20 of 29 Posts

·
Registered
Joined
·
264 Posts
Discussion Starter #1
Hiya all,
My van just failed it MOT and i am at a bit of a loss as to what to do next!

The report says:

RBT Front Brake Impalance:
He explained that one of the front brakes wasnt working or coming on as well as the other. Now the guy couldnt tell me what side was at fault as he said the machine doesnt show that?? I thought that it would!!

Anyway, where do i go from here?? I know that the pads are ok, the dics are ok but are a bit worn, the RHS front brake does squeel a bit, (which i suppose could mean its a bit seized, but thats all i have to go on!!

Any ideas would be appreciated!!
Thanks in advance!
 

·
Registered
Joined
·
399 Posts
Hi Wehey..my old T4 failed on exactly the same fault. I got 2nd hand calipers from a VW breaker at angmering and fitted them. I would guess one of the caliper pistons are seized/ or semi seized. It really bugged me coz when I got the old ones off only one caliper was faulty......but what price for your safety?. In retrospect I could have tried using a brake cleaner to free up the pistons but at the time I just wanted the job done . About 25 quid a caliper I think but they were as good as new...I also put new discs and pads on to be sure. Discs from GSF, pads genuine vw.
 

·
Registered
Joined
·
329 Posts
The brake roller or plate tester should be able to tell you the side thats at fault. as for the squeel it could be just the pads stuck in the cliper carryer.
for an in ballance it could be a sticking or seased caliper, pads stuck in the carryer, a shead brake pad, a fault flexy brake pipe ect. All the brake lines r check on mot so wouldnt think that. If it was mine id strip the brakes and clean all the carryer and pads, re copper eases them and check the pistons go back freely there will be some resistace. garry
 

·
Registered
Joined
·
399 Posts
Good advice from Garry there wehey, just a couple more things, if your going to do a serious job of freeing up the calipers as suggested,personally I'd crack the bleed nuts to make pushing in the pistons easier. you need to be careful and watch out for squirting brake fluid everywhere, but you may find without cracking them pushing them in is hard work, especially if there seized!!. If the rubber seals around the pistons are split/perishing personally I'd change the caliper. Anyway, I'd loosen the bleed nut to push pistons in....then tighten the bleed nut again and apply brake pedal to push out. Watch your fluid level. If your thinking about doing this, I'd also consider taking the caliper and carrier off completely to do a proper job of refurbing. As garry says, dont forget your copper ease!!.When you've done you need to bleed the system. T:
 

·
Registered
Joined
·
329 Posts
I second that extra advice! that is the correct way of pushing the pistons back. but as i work on them every day and vw dont give you the time for the brake bleed i dont. bad practice i know, but every tech and mech i kown doesnt. but if you deside not to release the bleed niple dont push the piston back too fast, just slow constance pressure. too fast and you can spin the seals in the master cylinder then ull need one of thoughs too lol. oh and dont try as see if the piston move freely with the brakes striped, or be very careful if you do cos you may push the piston out the caliper. ur need a seal kit then and make sure everything very very clean. garry
 

·
Registered
Joined
·
264 Posts
Discussion Starter #6
Thanks for the advice guys. I was thinking that it was a calliper!

The guy at the MOT'ers said that on 95% of the time new discs and pads will fix it but i wasnt convinced by this!!

I think i will try the angmering breakers and get new callipers 1st and then take it from there.
 

·
Registered
Joined
·
776 Posts
Thanks for the advice guys. I was thinking that it was a calliper!

The guy at the MOT'ers said that on 95% of the time new discs and pads will fix it but i wasnt convinced by this!!

QUOTE]

This isnt unheard of
sometimes you can get grease or oil on the disk from say a failed cv boot etc, if this has happened then its very difficult to get the disk clean and the pads will be totally US.


I dont disagree with any of the other advise, its absolutely sound, its just that caliper replacement is quite an undertaking if youre a novice like me and it might be worth exhausting the other possibilities.

Phil
 

·
Registered
Joined
·
264 Posts
Discussion Starter #9
A caliper change is a piece of p**s on the T4. I am suprised at how cheap the disks are tho..

Worst case scenario.....i change the calipers and its not them, so i change the discs and pads too....total cost should be no more than £130
 

·
Registered
Joined
·
399 Posts
Its a tricky area phil, giving any advice on brakes, coz at the end of the day your life (or someone elses!!) may depend on them. Wehey is right, these jobs are not difficult once you've tackled them a few times and you follow the rules. As regards avoiding lots of bleeding;) "standard" procedure is too block the flexible brake pipe hose off just above the caliper, CAREFULLY, using mulgrips and something (thick rag or similar!!)to protect the hose from being marked/damaged by the mulgrip jaws. You dont need a lot of pressure to achieve your goal. Then remove the caliper... so you dont really lose much fluid and the bleeding is easy. I've always used a one man bleed kit (non return valve built in). I had a mate show me years ago, thats the key. Its skill passed on. I did learn a hellovalot from the trusty (infuriating!!)Haynes manuals tho over the years!.
 

·
Registered
Joined
·
329 Posts
Good way if you going to use molegrips is to get two deep sockets the will go over the jaws. long nose are the best then the molelys look like a pipe camp. good to no loads of guys give excerlant advise on here. garry
 

·
Registered
Joined
·
312 Posts
The brake roller or plate tester should be able to tell you the side thats at fault. as for the squeel it could be just the pads stuck in the cliper carryer.
for an in ballance it could be a sticking or seased caliper, pads stuck in the carryer, a shead brake pad, a fault flexy brake pipe ect. All the brake lines r check on mot so wouldnt think that. If it was mine id strip the brakes and clean all the carryer and pads, re copper eases them and check the pistons go back freely there will be some resistace. garry
As with most mechanical issues youll never know what they are until you start stripping them down. The above is a good place to start as a standard brake service. Once youve got them to bits you should be able to spot any issues with sticking pistons,split gaters etc.. if youve not done this before i would try to find someone who has who can give you guidance and have a look at them for you.What you might think is worn might be :ced. Your MOT tester should have been able to pin point the faulty side with no problem. But the benefit to you will be that if you strip both it may help you spot the issue. i would also avoid cracking open the brake fluid system unless you have to change the caliper
 

·
Registered
Joined
·
264 Posts
Discussion Starter #15
Ok. Now ive fitted the replacement callipers i got from Angmering breakers. Aparently they test all parts before selling them so they should be in good nick.

Since fitting ive noticed the brakes are dragging as i can smell them once ive stopped and the discs are too hot to touch after about 10 miles. This is happening on both sides. Any ideas. Could greasing the pins that hold the pads in place help??
 

·
Registered
Joined
·
399 Posts
Did you just change the calipers wehey?... No logical reason for all brakes to bind on unless the problem lies in the master cylinder, which ,if there wasnt a prob before you fitted the calipers also doesnt make sense:confused:
 

·
Registered
Joined
·
264 Posts
Discussion Starter #17
Did you just change the calipers wehey?... No logical reason for all brakes to bind on unless the problem lies in the master cylinder, which ,if there wasnt a prob before you fitted the calipers also doesnt make sense:confused:
Yeah i just changed the callipers. I did read on the net that the pins that hold the pads in place may need greasing to allow the pads and calliper to retract a bit after braking, so i will give this a try tomorrow.
 

·
Registered
Joined
·
264 Posts
Discussion Starter #18
UPDATE:

Well ie taken both sides apart and greased everthing i can but still the same problems which seem to be getting worse.

After a 10mile ride today i jacked up each corner and spun the wheels and they seemed fairly free but each disc is so hot you cant touch it and they smell too. Even the back wheels are doing it now!!

The brake pedal is unusually stiff and the handbrake seem to be too!! I cant understand what is happening here as all this was fine before fitting the new callipers.

Out of interest, what is the recommended brake fluid for the T4. I used DOT 4 but i know there are different types.....the only thing it could be is the master cylinder but i dont understand why that woud be the cause as there was no probs like this before the calliper swap!

Anyone got any ideas??
 

·
Registered
Joined
·
264 Posts
Discussion Starter #19
Ive just had a thought.....

Do you think it's possible that when i clamped the flexible brake fluid hoses when i changed the calliper i could have damaged the hose's internal wall making it act like a one way valve??
 

·
Registered
Joined
·
399 Posts
I've clamped brake hoses loads of times and never had a problem with damaging hose walls. I've seen pro mechanics do it also, in fact it was a mechanic that showed me how to do it in the first place. I've heard of the problem of hoses perishing on the inside and creating a "one way valve" effect, but never had the prob myself. you could try changing the hoses, but why would they affect the rear brakes??. I've fitted second hand calipers on front and rear of a t4 in the past and never had a prob. All I did before i fitted them was to give them a good clean with brake cleaner and check the pistons were operating correctly. then pushed them back in carefully so I could get the new brake pads in more easily, (loosened the bleed nut to push them in fully) then bleed the system. I use dot 4 fluid I think. The problem seems to point to the master cylinder. Why it has chosen to go :c up at this point is a mystery to me.
 
1 - 20 of 29 Posts
Top