rear brake pressure

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OwenS
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rear brake pressure

Post by OwenS » Sat Dec 03, 2005 8:06 pm

My 14 TGE has gone in for its pre MOT check up and they have found that the rear brakes have no pressure going to them and have seized on? any ideas? :roll:
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ken newbold
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Post by ken newbold » Sat Dec 03, 2005 8:08 pm

Do they need bleeding from the dosseur valve.
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Post by OwenS » Sat Dec 03, 2005 8:10 pm

they said they had tried bleeding them but nofluid was coming through? i'll double check tho....any other suggestions out there????
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Post by tom » Sat Dec 03, 2005 8:34 pm

bleeding rear brakes is done with the engine running and the system under pressure with nornal height selected. The feed is from the height corrector so if it has closed off the rear brakes, no fluid gets through. Siezed calipers are common though and the whole lot should be stripped and cleaned up. The bleed nipples have at least been undone to bleed it so that is the biggest problem out of the way.

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Post by OwenS » Sat Dec 03, 2005 9:01 pm

latest is possble air in system....might have to get all new rear braking system if its been seized up for ages.....£££££££!!!! Think if that was the case she'd be crushed
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Post by AlanS » Sat Dec 03, 2005 9:03 pm

I have what I believe is a simple solution to bleeding rear brakes. It's a scissor jack off an old Toyoya Corona that I've used for years (the jack not the Corona) :P
I jack the car up and remove the road wheel and this jack has a [] style fitting which in the case of the Corona the jacking point sat into the top of. This is about the size of a brake disc thisckness, so I sit the disc in there and apply just enough pressure so that if you touch the jack or axle stand actually holding the car up, it feels loose without actually feeling as though you could pull it out from under the car, as a result, all the weight of the car is sitting on that rear wheel and you'll find fluid will flow so hard from the bleeder that I actually bled a couple of systems earlier this year where I pulled about 500 mls from each side in seconds. On occasions where my Corona jack wasn't available, I've jacked under the arm.
Regarding the rear calipers seizing; I did my sons rear arm bearings a year or two back now and last week, I pulled the arms off again to get the grease nipple mod done to it.
Whilst it was off, I decided to check how the calipers were as I'd remeoved them (they had seized) last time, cleaned and used a thin coat of silicone grease over them before reassembling. They slipped out using my index finger, easily and smoothly, so as a suggestion, strip them, wash in petrol and wipe over dry. Then put a nice thin coat of silicone grease over the pistons when you reassemble as mine felt as though they were going to last forever.


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Post by tom » Sat Dec 03, 2005 9:06 pm

Air in the system? Obviously.

That is the reason for bleeding in the first place.

If enough air was coming in to make this an incurable problem, you'd have lots of LHM coming out methinks and rear suspension that didn't work. If you don't know what you are doing yourself, at least take the car to somebody who does. Your current garage does not appear to be that somebody.

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Post by AlanS » Sat Dec 03, 2005 9:17 pm

tom wrote:Air in the system? Obviously.

That is the reason for bleeding in the first place.

If enough air was coming in to make this an incurable problem, you'd have lots of LHM coming out methinks and rear suspension that didn't work. If you don't know what you are doing yourself, at least take the car to somebody who does. Your current garage does not appear to be that somebody.
Ain't that the truth; I wouldn't like the words "Brakes" and this guy mentioned in the same sentence. Sounds like he's either out of his depth or lining you up to milk your wallet.


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Post by ken newbold » Sat Dec 03, 2005 9:31 pm

One other possibility I've come across in the past, the bleed nipples can become so full of crap and rust they need a stiff wire or fine drill to clear out the hole.

I've seen this on a few occassions.
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Post by OwenS » Sat Dec 03, 2005 9:32 pm

lol...well I'd be pretty stunned if he was ripping me off as he's my dads best mate and has been maintaing our families cars for the past 20 or more years!!! He is not, however, a Citroen trained technician or anything like that and has little to no experience with Citroen hydraulics. I have also asked to be informed of every little flaw they come across while looking over the car and this is all they have found, so on that score im relativly pleased....unless anything else is found..lol. All this could be down to something like an LHM change being done without rear brakes being bled?? if that was the case would this be an easy fix?
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Post by DavidRutherford » Sat Dec 03, 2005 9:33 pm

I've always thought it was best to bleed rear brakes with the suspension in "high" so that there is maximum fluid pressure available, and the height corrector is wide open, meaning there is full-flow of LHM available.

A neat trick to avoid wasting LHM is to fit a 12' length of clear washer hose to the bleed nipple, poke the other end back into the LHM tank, open the bleed nipple and then stand on the brake. You can then bleed litres and litres of fluid through, absolutely guaranteeing that the system is clear of air, and not wasting any fluid. It's often amazing how much fluid you can bleed before air appears.
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Post by tom » Sat Dec 03, 2005 9:49 pm

As I said before, this needs to be done by somebody who knows what they are doing. Somebody untrained in Citroen hydraulics should read Haynes, which covers the subject with uncharacteristic( :) ) correctness.

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Post by OwenS » Sat Dec 03, 2005 9:59 pm

Yeah, for most things I find my haynes manual useless!! I would have quite happly worked on car myself..with help but my dads mate is in Wales and Im in Newbury, where I have no where to work on car in safety and can't afford normal garage prices...so get cheaper service at this place and work is usually excellent. They now have my BX haynes manual.....fingers crossed!!!!
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Post by adamskibx » Tue Dec 06, 2005 9:28 pm

Hi Owen. I had a BX 14 with non functioning rear brakes- You could tell as it was stupidly easy to lock the front wheels up. In this case, it wasnt the calipers that were siezed, but it was the pads themselves that had rusted onto the caliper due to the car being sat for a length of time. Even full braking with people in the car was obviously never enough to free them so I literally had to wack them out with a hammer and chizzle to free them up. Just thought id mention it in case the mechanics havent already checked this. If they have then proceed as other people have already said, bleeding the brakes in the way that the haynes says (which I think is the way David says to do it with the car at top height). As the garage now has the Haynes I cant see how they can go wrong if they follow it step by step.