Citroen AX 1.5D brake issues

[3ps]

So onto the next problem, the brakes.

Now the brakes are not what you would call strong, but if you press them hard they stop you, it's just a bit old fashioned feeling, but I guess even though it is a 1995 we are talking late 80's technology, at best. Overall, I can live with the brakes.

However I am experiencing the following symptoms and hopefully those more knowledgeable than myself will pinpoint the issue to something specific.

Symptom 1
Sometimes, when I press the pedal, it doesn't feel quite right, then it gives a little clunk as if there was something blocking it and the pressure I put on suddenly gets it passed that bit and then it operates as normal. This is intermittent and some days I don't feel it at all.

Symptom 2
This only occurred today. I was on the motorway and braked and it pulled to the right. I lifted off and it snapped to the left. I tried it a few times and it repeated. The car has always had a slight instability but it has not affected straight braking to any degree that would cause me concern, I had put it down to some front suspension wear, or engine mount wear.

This was much different and much stronger. I dropped back from the cars in front and tested it a few times and it repeated.
Then all of a sudden, it went back to normal operation.


Hopefully the two of the above might allow somebody to go "oh that's obviously a sticky caliper" or "brake cylinder FTW" etc

Many thanks.

[Chris570]

i'll give you some food for thought....

the AX's have a brake bar that runs across the bulkhead and that is a bar with a hook affair that presses on the master cylindar, that hook can cause problems (although rarely) It's behind a rubber cover on the bulkhead roughly behind the top of the brake pedal.

AX's also like to get leaky rear cylindars so i'd have a look for dampness and check for fluid level drops and if all of that shows up good give it a thorough bleed through.

That should rule out a fair chunk of issues. I've not heard of sticky calipers but again i wouldnt rule it out

[spider]

The link bar does make them feel a bit different, however they should work fine. If possible really you need to try the brakes on another one or a 106 / Saxo for comparison.

They do feel strange but they should actually work fine.

The one design of caliper that commonly seizes is the one with the two long pins holding the pads in, I forget which make it is but I think that's only fitted to the smaller petrol engines.

[3ps]

I have just learned that in the last year or so the car has:

The master cylinder was replaced or is that the slave cylinder - the bit with the fluid bottle - I even think the master cylinder was replaced too - most of the back brake set up was upgraded with new cylinders and pads etc.

[spider]

Master cylinder is the one with the bottle (reservoir) under the bonnet. Master cylinder replacement is relatively rare.

The rear cylinders (slave) in the rear brakes is more like it and reasonably common.

I used to be told they failed because of lack of brake fluid changes, however having serviced some cars from new that have had brake fluid changes on time and properly (I know, I did them!) they still failed...

It does shorten their life a bit though to be fair plus old fluid = not terribly good.

[citronut]

the linkage across the bulkhead ( behind the engine ) does seize up at the pivot points one at the pedal end and the other at the master cylinder/servo end,

also the front caliper ( Teves ) sliders seize up as the slide pins run through a nylon sleeve inside a rubber bush, the alloy casing were the bush fits corrodes, which in turn crush's the bush and nylon sleeve and this then bind's on the slider pin

[3ps]

I'm not familiar with the rear cylinders... do you mean inside the caliper?
So essentially, the easy fix would be to put a new caliper on (if it was found to be leaky).

I reckon the labour involved in stripping and fixing seals might be too much?

[citronut]

the rears are more likely drum brakes not disc's and calipers,

if they are drums these will have wheel/slave cylinders in between the brake shoes, this is what Andy is saying,

i would check the front brake calipers are working properly and sliding on there sliders,

then check all the linkage's are free and not seized/binding, usually just need lubricating at both end pivot points