Calliper confusion?

[Juuls]

I posted a calliper topic a couple of days ago but had no response. This is just an update and i'm still after some kind of explanation or answer from anyone on here.
Have just returned from the garage (again) with my offside right calliper smoking like hell (with fierce burning smell) and it's obvious that it's sticking because the van isn't accelerating as it should. The garage initially inspected the van a couple of days ago and i was told me that the problem is in fact my nearside left and not the offside right calliper. So have ordered a nearside left calliper replacement to be fitted this Saturday. Which has left me rather baffled because the offside right is where all the burning and the burnt smell is coming from. What the hell is going on? How's this possible? Does one calliper affect the other calliper? Is the garage right or have they made a spectacularly bad assessment and don't know the mechanics of a T25? The answer will surely come on Saturday after they have fitted the nearside left calliper and then we will see if the offside continues to smoke and smoulder.

[lloydy]

Well if the one caliper was seized and the other was doing all the work then I guess it could overheat and smoke.

[colinthefox]

Maybe this should be in Mechanical?

But anyway...........sticking calipers are usually caused by water getting past the seals and rusting the piston in the body. Not rusted absolutely solid, but enough to prevent the piston retracting once the brakes have been used. Cure is usually a new caliper. Sometimes (not often) a brake pad will rust in its location. Cure is to file off the rust and clean up the location in the caliper. Occasionally a very old flexible hose will close up due to the rubber perishing and will have more or less the same effect. Cure is a new hose.

I know of no way that the caliper on one side can affect the other side.

This issue is common to most vehicles, and no specialist knowledge of T25s is required by a garage, except where to find the brake fluid filler cap.

[E D I T] Doh! Lloydy got there first![/E D I T]

[shepster]

You need to jack the van up and see which side is dragging, as said already unlikely to be caused by opposite caliper as brakes only 'work' so hard so unless you've been on a track day I can't see how smoking and burning can happen under normal use.

Another cause of the piston sticking is when the groove the seal sits in becomes corroded and forces the seal to become tighter on the piston, simple enough to fix, caliper off, remove seal and clean groove out, replace and bleed brakes.

You can see whether the pistons have rusted while you're at it and replace them if needed.

If money allows the easiest is to just replace the whole caliper of course.

[Juuls]

Thanks for response. I did post this in mechanical as well, but had no answers there. The situation is just really really odd and baffling. The garage tell me the problem calliper is nearside left…..but you can actually see smoke (and get a burning smell) coming from the offside right. The garage have totally ignored what i've told them (and what you can physically see). It's like a vet ignoring what the pet's owner is telling them. Surely that's an important rule to follow? One thing's for sure…..if the problem persists after they've fitted the nearside left calliper, they'll be getting a bollocking from me.

[colinthefox]

..if the problem persists after they've fitted the nearside left calliper, they'll be getting a bollocking from me.

Quite right too! But you'll probably still end up paying to get the other one changed as well.

[greasemonkey]

Shepster has the right idea, jack up and see what's binding.

I'd take the pads out and start by giving everything a good clean out and potentially replacing seals etc as above.

Depends how mechanical you are, if not the you are at the whim of the garage unfortunately and hopefully they know what they are talking about, but it does sound a but weird from what you describe. Make sure whatever happens you get your old caliper back off them. I wouldn't be surprised if you could clean it up and if not too corroded could sell on ebay to make some money back.

[Dazco]

If you don't trust the garage with the diagnosis, then take it somewhere else for a second opinion. If was that sure the garage had got it wrong there's no way I would let them any where near my van and especialy not the brakes.

[Oldiebut goodie]

Surely the diagonal circuits means that the nearside left cannot affect the NSF and vice versa. Normal setup on most vehicles, surely the garage would know that?

[123-jn]

They are usually both the same vintage so always best to replace both and maybe discs at the same time if they are not great.

[manxblade]

I had the same problem last week and replaced discs, calipers and hose's it turned out that the hose had collapsed internally.

[bigherb]

Surely the diagonal circuits means that the nearside left cannot affect the NSF and vice versa. Normal setup on most vehicles, surely the garage would know that?

T25 brakes are split front to rear not diagonally.

[Juuls]

Thanks for all the advice. Have decided on the sensible….replacing BOTH front callipers and fitting new brake hoses AND taking it to another garage.

[Oldiebut goodie]

Surely the diagonal circuits means that the nearside left cannot affect the NSF and vice versa. Normal setup on most vehicles, surely the garage would know that?

T25 brakes are split front to rear not diagonally.

I stand corrected - spent so much time on normal diagonal circuits this last couple of years on other vehicles. I'd never considered that they weren't 'normal'.

[Smcknighty]

When I first noticed that I thought I had single circuit brakes. A scary design only implemented on very early T25's. Mines an 82 so it was feasible.