Caliper Plates

[Hilux]

Then I took the pads to a bench grinder and gave them a wee grind down either side and they then went in with ok'ish.

Consider this also even with new pads and refurbished calipers.

Even if the pads and seats are ok, if the pads are an interference fit ie; move but keep contact with the sliding surfaces then what happens when they (and the caliper) get hot and expand!

Not all pads are manufactured mm perfect so if I dont have free movement when cold I run a mini grinder along the contact surfaces of the pads until they run truly free. I also round off the edges a little with just a glance from the grinder. This can sometimes increase squeal a little unsprung pads but when on track or hustling on a road it does allow the pads to `relax` properly away from the disc. I also use coppergrease on the bearing and sliding surfaces. The solvent burns off and leaves a lubricating film of copper.

Mono block caliper pinned only pads can be heard rattling. If I took the tension springs off my Golfs fronts they would rattle also. I prefer the pads to be loose when cold.

 

[diabloam]

this is all interesting reading the now as i know I am going to have to go back and readdress this, battling with belts and water pump the now and then have new shocks and 968 castor mounts next but its is on my list to do my calipers properly again and maybe go full hog with a repaint etc. I fancy after reading this that I maybe should have persevered with the mig route at time was just wanting the car back mobile at the time, this is defo an area where everybodies advice is well appreciated, think this is something just about everybody experiences with the brembo calipers! good stuff!

 

[robwright]

OK I took the plunge and started a test refurb on one of the calipers I have some photos of the beginning, middle and end. Hope you are as impressed as I was. Can't wait to get the others done.

Shocking the caliper screws with a punch.

Welding bolts to the screws proved the only way to get them out

First coats of paint after cleaning the caliper up.

A top coat using my spray gun. Will probably do the rest just with the spray gun. Thought a brush coat first may give it more depth but on reflection enough spray coats should do just as good.

The refurbished plates and spring prime and painted ready to go in.

And finally the finished article. Just waiting on new stainless screws for the plates and it is ready to go back. Can't wait to get all four done!!!

 

[Hairyarse]

Top work mate, I'll come over and drool over all 4 when you have them done

 

[os951]

Good work.
I don't even bother try to remove original screws without MIG welding another ones to originals, makes things lot more easier .

 

[zcacogp]

Just seen this thread ...

The bolts are standard M6, and you can use ones with regular external hexagonal heads (i.e. regular bolts); if you file them ever so slightly thinner then they will clear even thick, new pads. This will make them much easier to get out when you next do the job.

Oh and stainless bolts are definitely the way forward for this sort of thing.

Those like some very handsome calipers now Rob. Good job.


Oli.

 

[robwright]

Oli the bolts are actually M4 but I can get some stainless M4 button heads for nowt off my bolt supplier so just at my favourite price. Oh PS I don't ever intend doing it again lol []

 

[zcacogp]

M4? How stupid of me, I knew they were M4 (I have the old ones rattling around on my desk in front of me too!) - why did I type M6? Thanks for correcting me. The benefit of using a normal-head bolt is that it will be much easier to remove if necessary, but if you never intend doing it again then this won't be a problem!

(The design of the caliper is such that it encourages corrosion, and is a poor design. I did consider bolting a sacrificial anode to mine once I had repaired the plate lift, which should significantly reduce any further corrosion. However yachting shops wanted stupid amounts of money for tiny lumps of zinc, and I couldn't work out an elegant way of bolting something with suitable surface area to the caliper without drilling holes in the caliper - something I was reluctant to do for obvious reasons. I lost interest and dropped the idea, but someone else may be able to do better.)


Oli.

 

[Lowtimer]

This might be the stupidest question ever, but to built on Oli's point, is there anything to prevent a person getting the caliper body zinc plated? That would certainly give it sacrificial protection.

 

[zcacogp]

Oooooh, good question Simon!

>AwaitsAnswerWithInterest<


Oli.

 

[rcsalmons]

Oli you typed M6 because they are M6 x 16mm.

Rich

 

[Super_Marv]

ORIGINAL: Lowtimer

This might be the stupidest question ever, but to built on Oli's point, is there anything to prevent a person getting the caliper body zinc plated? That would certainly give it sacrificial protection.

Could be wrong, but I thought that plating aluminium alloy (which the caliper bodies are made of) won't work, because Zinc plating only offers sacrificial protection for ferrous metals?

Edited to add - Great work on refurbishing the calipers Rob...they've come up really nice []

 

[Lowtimer]

Of course: you are right. Should have worked that out for myself. Being largely aluminium, the caliper itself is one big sacrificial anode to the plates.

To provide a sacrificial anode to the light alloy, the only thing you could use would be magnesium.

 

[944Turbo]

The aluminium outboard leg on my boat has zinc anodes,
Tony

 

[Frenchy]

Rob,
Is that your astronauts helmet behinc the vice []
What size are the bolts then 4 x 16 ?

 

[Hairyarse]

ORIGINAL: Frenchy

Rob,
Is that your astronauts helmet behinc the vice []

Lmao[]

 

[Frenchy]

[]

Are they 6M or 4M

 

[robwright]

Frenchy my apologies and Oli they are indeed M6 after having just offered one up to an M6 nut. In my defence I was actually going by an article on 911 world [&:] Better phone my supplier and change my order to M6 x 16mm. And frenchy yes that is my astronnaut helmet to prevent further oxidation I prefer to refurbish the calipers in the vacuum of space []

 

[Mike_Pollock]

Best join the club and get a proper mag []

 

[bluedexter]

From our experience in the manufacture of deck equipment for the fishing industry, it is essential that any contact between aluminium and stainless steel is avoided. If you study the information on this link you will understand the reason for this.

http://www.engineersedge.com/galvanic_capatability.htm

There are two options;

1. to insulate the contact area
2. to use a metal other than stainless steel which is closer in the periodic table.

Has anyone tries zinc plated steel for instance?