brake overhaul

[robb4100]

Hi Folks,

I am getting a horrible squeal from my front brakes and also noted that the front pads are dragging a bit on the rotor so I decided take the assembly apart to see what I could find

The pads have lots of life
Is this normal wear for where the piston meets the pad?

brake pad wear

I assume that this red gummy crap is not supposed to be here

Gunk on piston

Could the abrasive action of metal to metal be probably causing the squeal?
two of the pistons need to be replaced- Small scoring in a ring around the piston
Should I be concerned about this pitting and wear pattern in the bore?

wear pattern on pore- small pitting rust on outer ring

Finally should I be concerned about the rust and corrosion just outside the bore? There should not be any interaction with that and the piston.

I plan to completely flush the system and rebuild master cylinder before putting this back together and would love comments-questions and advice

Robb

[PeterK]

The 'red gummy crap' is most likely red rubber grease. This type of great does not affect rubber, so is the only safe grease to use around brakes. It lubricates and keeps corrosion at bay, so is good stuff. However, any grease captures air borne brake and road dust, then acts as an abrasive, so use grease very sparingly.

Corrosion outside of the seal should not be an issue, as long as it doesn't touch the piston or rubber seals, or impact structural integrity.

Assuming that the squeal goes away when you apply the brakes (noise caused by brake pad vibration), rather than starts when you do (noise caused by over-heated pads). Some brake calipers use anti-squeal shims, although yours looks like the type that don't. For these, some brake pad sets come with a very thin rubber sheet to do the same role. Failing that, a very light smear of red rubber grease may reduce the squeal

Peter

[Galwaylotus]

This is what overheated pads look like!
I subsequently had both front calipers rebuilt by Classic Car Automotive and they came back better than new! Disc hadn't warped so I just needed new pads for the rebuilt calipers.

[robb4100]

Thanks Peter,

Good to know about the red crap- it is cleaned up and I am ready to go. The brakes squeal when they are applied - seems worse when warm but I can hear it within first 1/2 mile.

Galway lotus- so very glad my pads don't look like that!

What type of Pads do folks recommend?

Robb

[twincamman]

Ok....my experience with brake squeal has been too gentle use of the brakes causes high spots to build up on the pads . I take the car and do two or three Hard braking stops from 60 or 70 MPH, making sure no one is behind you , solves the problem for me ....Ed

[alexblack13]

There is a set of anti squeal shims available for those calipers.

Fit them and apply some copperslip to back of pads and you should have no more squealy noises.


Al' ....

[pharriso]

There is a set of anti squeal shims available for those calipers.

Fit them and apply some copperslip to back of pads and you should have no more squealy noises.


Al' ....

+1

[pereirac]

I seem to remember they look like this

http://www.ebay.co.uk/itm/VAUXHALL-VIVA ... 2c7cf204eb

Carl

[pharriso]

I seem to remember they look like this

http://www.ebay.co.uk/itm/VAUXHALL-VIVA ... 2c7cf204eb

Carl

Yes that looks like them, odd shaped things!

[PeterK]

There is a set of anti squeal shims available for those calipers.

Fit them and apply some copperslip to back of pads and you should have no more squealy noises.


Al' ....

But use as little CopperSlip as possible and be careful where you put it. It will cause the rubber seals to swell if it comes into contact.

[Plus 2]

Robb,

I always fill the caliper piston seal covers with the 'red gummy crap' (rubber grease).

The problem is brake fluid absorbs moisture through the seals microscopic pores. It is this moisture that causes the corrosion build up around the caliper and piston which the red rubber grease in my opinion puts off the problem of stuck pistons a little longer.

Anti-squeal shims as described should sort out your squeal no problem as they did for me. I had a squeal due to sticky piston on one side of the caliper and also a click when I accelerated gently or braked lightly which I thought was a loose steering rack, chassis bolt or shock absorber issue as I had already changed gearbox and engine mounts. Turned out it was just the small movement of the brake pad as it moved up and down a bit in the caliper. I might add it was about 15 years ago the calipers were last overhauled and I have to confess only a couple of fluid changes too over the years

Regards

Steve

[mariodschy]

Robb,

I always fill the caliper piston seal covers with the 'red gummy crap' (rubber grease).

The problem is brake fluid absorbs moisture through the seals microscopic pores. It is this moisture that causes the corrosion build up around the caliper and piston which the red rubber grease in my opinion puts off the problem of stuck pistons a little longer.

Steve

Whit DOT 5 breakfluid this problem could be avoid because this slicion fluid doesn't absorb water.
I have to rebuild the hole brakesystem and i'll change from DOT 4 to DOT 5, the main Problem ist that when you change to DOT 5 all Gaskets and all break hoses have to be changed becaus the DOT 4 Fluid creep in to the rubber.

[rgh0]

[quote="mariodschy
Whit DOT 5 breakfluid this problem could be avoid because this slicion fluid doesn't absorb water.
I have to rebuild the hole brakesystem and i'll change from DOT 4 to DOT 5, the main Problem ist that when you change to DOT 5 all Gaskets and all break hoses have to be changed becaus the DOT 4 Fluid creep in to the rubber.[/quote]

Dot 5 does not absorb water but water will still be getting past the seals and sits in the calliper cylinders as free water and causes corrosion all the same. The DOT 5 is also an issue with its compressibility giving a soft pedal with long travel in an Elan.

Personally I would use a DOT 3 (if your into originality) or 4 (can potentially affect some of the original rubber components in an Elan brakes but these have / should have been replaced by now) or 5.1 ( if racing) fluid and change it regularly every 2 years.

cheers
Rohan

[mariodschy]

@robb4100: Saw that you have split the calipers, what seal is between the calipers? I found a Repair Seal Kit on ebay but the seal between the calipers is not included and the seller recomend not split the caliper because the seal between is "not user serviceable"

[patrics]

Hi
Regarding the comment about dot 5 fluid if you look at the photos there is no corrosion in the caliper bore where the fluid actually is, its on the out side of the system which is what you would expect from cast iron.
If you want your braking system to function properly use what's recommended by the manufacture which these days in Europe at least is dot 4 or dot 5.1.

Regards
Steve