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Discussion Starter #1
Hi,
Got a T4 with disc brakes all round.

There was a plate under the right rear as part of the Mobility conversion and that was lying on the handbrake cable and as far as I could tell meant the rear brake was on - the wheel was very hot to the touch (I think both wheels from memory?)
Once tha plate was out the way, all seemed fine, but now I am noticed the rear right/offside wheel is again very warm to the touch - not too hot to touch as before, but definately warm - and the other wheels are stone cold.

Could this previous issue with the handbrake cable have caused an ongoing issue?
Any ideas what is likely to be the problem just affecting one wheel? Sticking pot in the caliper?

TIA T:
 

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Jack the rear up and release handbrake. Spin the wheel. If the caliper is sticking it will show up.
Check the handbrake mechanism on the caliper to see if they are releasing properly. Then check the condition of the handbrake cable. Mine were seized. I replaced the two rear cables. £12 for the two from Ecp.
 

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it could be either the cable/s or the actual caliper itself, occasionally the calipers seize inside.
 

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Discussion Starter #6
Not had a chance to look at this until today ...

So recap:
My rear offside wheel is binding. If I drive about 3 miles and then feel the wheel it is hot to the touch, while the other 3 wheels are still stone cold. If I drive a fair distance, the wheel is too hot to touch.

I jacked up the rear and tried to spin the wheel...
With the handbrake off, I can turn it, but it is certainly not free to spin.
With the handbrake on, the wheel won't turn. So the handbrake IS working, at least to a degree (whether totally right I don't know?)

Here is a photo of the rear hub/disc - I don't know if this will be any help or not, but where should I go from here? :confused:

 

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Those look a bit scabby which makes me think the braking mechanism isn't working quite right. Have u checked the slider pins for rips? Do the calipers float well on the pins. If they look ok I'd drop the caliper off and wind the piston in a bit and also check for the presence of an outter dust seal on the piston. The Pistons can be difficult to twist in and push at the same time but u'll know if it's seized as it won't twist at all.
Also while ur there drop the handbrake cable off and check the handbrake cable isn't seized. It's all stuff u can do but fiddly.
If all checks out I'd look into the servo.
 

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looking at that photo i would seriously service them calipers at least. my guess is its not sliding as its rusted up.
 

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Discussion Starter #9
The pads and discs were replaced 3 years/13k miles ago. It would seem they did the minimum needed, probably for an MOT, as time work done pretty well coincided with MOT anniversary.

So caliper service vs caliper replacement .... Service fairly straightforward with strip down etc? I guess the same requirements re fluid replacing, bleeding, etc, applies to both, so a service will be basically more time-consuming but significantly cheaper? (Right now I am more time-rich, money-poor :( )
 

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Discussion Starter #10
Those look a bit scabby which makes me think the braking mechanism isn't working quite right. Have u checked the slider pins for rips? Do the calipers float well on the pins. If they look ok I'd drop the caliper off and wind the piston in a bit and also check for the presence of an outter dust seal on the piston. The Pistons can be difficult to twist in and push at the same time but u'll know if it's seized as it won't twist at all.
Also while ur there drop the handbrake cable off and check the handbrake cable isn't seized. It's all stuff u can do but fiddly.
If all checks out I'd look into the servo.
The handbrake application defiantly does do something on that wheel, so I am guessing is not seized.
I am getting this problem on one rear wheel only (based on having that one wheel running very not when others are stone cold) so that would say the servo is probably ok? And issue isolated to that specific wheel braking section only?
 

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Hoovie,

I't can't be servo as only one disc is affected.

What I would try is when the wheel is binding crack off the bleed nipple to the caliper and see if it frees off, it could be that the flexible brake hose to that caliper has become slightly delaminated internally. Causing the fluid to struggle to return back.

Worth a shot in my opinion.
 

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It probably isn't servo related hence why I said get the caliper of first and check the slider pins; free, then check the piston movement; free!
If the caliper needs rebuilding check the piston size. I think it's 38mm and as luck would have it I've a rebuild kit u could use.
Check this link out to rebuild. It's off ukpassats.co.uk so I'm hoping the admins won't delete this. The caliper working is roughly the same so will guide u well if u need to rebuild seeing as u time rich....http://www.ukpassats.co.uk/phpbb/viewtopic.php?f=33&t=46203
U may have to register to see the listing but it's worth it if ur going down the caliper rebuild route. Seems like a damn good chap who did that write up......;-)
 

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Discussion Starter #13
It probably isn't servo related hence why I said get the caliper of first and check the slider pins; free, then check the piston movement; free!
If the caliper needs rebuilding check the piston size. I think it's 38mm and as luck would have it I've a rebuild kit u could use.
Check this link out to rebuild. It's off ukpassats.co.uk so I'm hoping the admins won't delete this. The caliper working is roughly the same so will guide u well if u need to rebuild seeing as u time rich....http://www.ukpassats.co.uk/phpbb/viewtopic.php?f=33&t=46203
U may have to register to see the listing but it's worth it if ur going down the caliper rebuild route. Seems like a damn good chap who did that write up......;-)
Thanks for the advice John T:. Please don't think I am knocking your comments about the servo, I'm just posting my thought process up there :) and I do appreciate that you posted "check the servo" comment after you say to eliminate a bunch of other stuff :)
I'll bookmark that link in readiness. My brake disc is the 280mm one for the 15" rims (if think the 16" rim setup has a 294mm disc?) if that helps work out the piston size?

Digger Dub .. I'll give that a shot. Sounds like a quick test (if the nipple frees off, of course! Last time I tried tweaking nipples it was on a Suzuki Swift brake cylinder a few months ago and they just would not budge.)
 

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I had this problem on my off side rear getting hot and after cleaning and greasing all the calliper parts, sliders/pins, I also got a re-build kit for the calliper which replaced the rubber seals for the piston, new pads and discs never had a problem since.
 

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Wouldn't bother with rebuilding them both. I'm a believer of if it ain't broke....etc etc.
just sounds like u have a sticky caliper that's all and that could either be slider pins or seized piston in the caliper.
 

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I had this problem on my off side rear getting hot and after cleaning and greasing all the calliper parts, sliders/pins, I also got a re-build kit for the calliper which replaced the rubber seals for the piston, new pads and discs never had a problem since.
Sounds promising T:

Reading around the forum, it does seem like the offside rear is far more prone to problems then the Nearside rear?
 

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hoovie. remove the caliper by undoing the bolts in the slider tubes, leave the hose and handbrake connected. my guess is the pins have seized stopping the caliper sliding. sometimes its also the actual rust where the brake pad fits in the caliper on the inner pad that holds the pad constantly against the disc. this is a very easy thing to check and is the most common problem.
next step would be to see if the piston is free.
sometimes even if the handbrake operates it, the cable can still be tight stopping that last bit of vital return.
good luck with it T:

if it was me i would do enough to get it through an MOT then sort it properly in the spring ;)
 

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Discussion Starter #19
I'll be looking further tomorrow hopefully :)

Got a fresh MOT back of September, but I don't like the way the wheel gets so hot so fast so don't want to leave in case I want to use the van in the next few months (on each drive it feels more and more like I am leaving the handbrake on with the dragging)
 
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