RESOLVED - Saga continues ! LHD Front Brake Calipers x2 -

[Betweenthewheels]

Hello again folks. So. It would appear that the problem has been resolved by Salters Garage.

On my first visit there, in addition to loosening bleed nipple, they thought that the near side front brake was seized and replaced the 'new' calliper with the 'old' one that was still in the boot and thought that brakes were no longer binding - note - no real road test of vehicle at this stage. When examining car they say that handbrake not operating on off side front wheel - cable disconnected on pedal yoke so this was also fixed.

However,
On my drive home after about 15 miles squealing brakes again.

Booked in for the week after....

Just collected my car again just now from Salters after explaining (again) nature of the problem and requesting that they field test car to diagnose problem as it appears to only happen at temp before they give it back to me again.

The rear brakes were squealing at 10+ miles - they cleaned and de-glazed them. LHM getting too thin at temp and pushing past doseur internals causing light braking to be applied. They sampled LHM fluid and the flow/return filters and saw they were dirty. They cleaned filters and reservoir, flushed system with Hydraurincage (1 unit £49.80), flushed/clean doseur and filled with fresh LHM. Have just driven 30 miles from garage this morning and all seems to be ok. Fuel consumption looks better than before, no squealing approaching lights and no tell-tell catching of brakes on drive off.

Hopefully this is it.

Thought I'd let you know how it went.
Thanks for all your help - this is a great resource

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Original Post Below



Hi folks - I wonder can someone point me in the right direction....

I've noticed that my front brakes of my LHD XM (Series 2) were squealing when braking after about 15 mins into a journey.
Thought it was the brake pads and had them changed.
Problem persists.
Garage now tells me that the front calipers are seizing and need replacing - not possible to grease these apparently as they are screw in.

Got an astronomical figure of 250£ per side so said I would go looking.

The problem is all the UK websites are offering parts for RHD models and the caliper I need would need to have the handbrake part on the left and the "normal" one on the right.

Both parts don't need to have the holder part of the assembly as that's ok.

Any suggestions?

I tried contacting Oscaro.com (online parts) that I used to use when I was in France but it would appear they won't ship outside of there.

Any help would be very welcome...

Regards, Ultan

[White Exec]

SFAIK, calipers are the same for LHD and RHD. No reason for them to be different.
The caliper piston is on a very fine screw thread, and needs to be wound in (clockwise) to retract it, eg for new pads.
A good few rotations are needed.
Simply pushing it (eg with a G-clamp) will not move it.
Wonder whether your garage has understood this?

Brake squealing is common on the small rear discs, which do very little work on XM (and other hydraulic Citroens).
Lots of light braking can lead to squeal on the rears.

For the fronts, do a bit of hard braking to de-glaze the discs, and clean up the caliper pad support surfaces so the pads are a smooth fit.
Coat the back of the pads with a layer of stiff copper grease, where they contact the caliper body and pistons. This accoustically couples the pads to the heavy caliper, and should prevent high-frequency pad movement (squeal).

Make sure the lug on the back of the inner front pads engages in one of the piston slots. This stops the piston from rotating further, and allows the self-adjusting mechanism to operate correctly, to compensate for pad wear.

[xmexclusive]

As stated there is no difference in brakes between LHD and RHD.
What engine does this VSX have?
Around 1997/8 the front brake types changed on just the V6's and 2.5TD's.
If they are the earlier type (283mm diameter discs) spares are cheap and in quantity.
If they are the later type (288mm diameter discs) spares are hard to find and expensive.
Very few of us have this later type on our XM's.
But the XM 288mm brakes have a reputation for brake squeal even in good order.
There is a simple fix that I think requires adding some sort of small spring.
One of the V6 owners with a very late car may know the detail.

John

[jamescarruthers]

I had brake calipers refurbished at EBC, by post and can recommend them.

[Dieselman]

Before condemning the calipers check the handbrake adjuster wind back parts do actually work and run some hydaflush through the system.
I have had binding calipers where stripping and cleaning failed to stop binding, which was fixed with a system flush.

[White Exec]

If flushing, make sure that the flushing fluid gets right through to the calipers, which are dead-legs . . . i.e. bleed until the new fluid appears uninterrupted at the caliper bleed screws.

[Dieselman]

I wonder if the binding is a result of residual pressure as a result of the Doseur valve not returning fully, hence flushing may work.

It would also be worth checking the caliper slides aren't binding.

[Betweenthewheels]

Thanks for all this great advice folks - I'm going to print them off and bring them to my local mechanic to see what's best - excellent!
Thanks a million for that.
Regards, Ultan

[Onion Johnny]

The above is all good advice I can recommend Brakes International in Bolton Rochdale area. Their website has really good information on sizes of pad and disc etc. One other thing you might check which caused my front brakes to bind was the brake valve under the front scuttle it has a lock nut to adjust the contact point of the piston in the valve with the linkage from the foot pedal, mine was a little too tight resulting in very slight brake application not noticeable when driving but obvious when trying to turn hub by hand. Also make sure the whole caliper slides smoothly on locating pin as well as the main slide pin. Fit the caliper without pads and the lower pin as well. I missed this on mine as I just checked the upper fitting. The lower bush looks like a clip to hold the wear indicator wire but it also provides the sliding surface for the lower pin to slide on. This is usually cruded up and the pin is often rusty too. Check it fits nicely into the little horse shoe opening for it on the cast part of the caliper body. I've even come across this part missing on a car I scrapped a couple of years ago. It looks like a shiny bit of spring steel when cleaned up.

[White Exec]

One more thumbsup Brakes International, Rochdale.
Just ordered a couple of sizes of bleed screw; order dispatched within 40mins of the web order.
Lots of useful data on their website.