Is it really necessary to grease the back of brake pads

[olddriver]

In June, I was 250 miles away from home and had to have the front brake callipers replaced.  

 

Now, my MOT man has informed me that there appears to be partially melted grease on the brake pads/callipers and I should change it to copper grease. Is it really necessary to grease the back of the pads, I've never ever applied grease to pads before.  The grease surely could collect grit that may affect the operation of the pads?

 

The previous history to this is here:-

http://www.toyotaownersclub.com/forums/topic/178435-intermittent-screeching-sound-from-back-wheel/

Additionally, they actually fitted new pads.

 

[oldcodger]

Hi,

Brake squealing and such like should be taken care of by the factory fitted shims, if still on the car,   but on some older cars this does not always work.

Some brake pads come with a type of rubber backing pad to help stop such noises and as such do not need copper grease, though many always add it anyway because you normally have to copper grease the pad holder clips.

Take your point about it attracting dirt, but in practice they do not seem to collect any significant debris.

Bit surprised a garage would use normal grease ?  wonder if they used some of the left over silicone grease from the new caliper etc ?

Also  they might have used  something like Cera Tec lubricant for brake pads, which does look like melted grease when its pressed out from behind the pads; often used to prevent pad rattle.

You can see what it looks like lower down on this link.

http://www.r32oc.com/topic/44339-guide-to-restoring-brake-performance-cleaning-your-brake-setup/

To strip out all 4 sets of pads and clean and correctly 'grease' them, about a 2 hour job if diy,  probably less for a good mechanic in a workshop.

Think I would first ring the garage who fitted them and ask exactly what they used.

 

[olddriver]

Thanks oldcodger.  Actually I have put loads of Vaseline on my Battery terminals and my MOT man described the grease on the pads as looking like the partially melted Vaseline.  Looking at your link, the grease in the pic (about 3/8 of the way down the page) headed "Apply some Cera Tec Grease to the Piston also" looks a bit like this partially melted Vaseline.  That seems like a very large amount of grease to me, too much in fact.

Is the Cera Tec Grease colourless and or does it look similar to Vaseline?

The car has done 140,000 miles and I have never applied grease to the pads and there has never been a problem but the parts I have used have always been Toyota, and I have never applied grease to any of the pads on the cars that I have owned and never had a squeak, but have always used original equipment, eg Girling.  If I clean the calliper up, I would be temped to not apply grease, however the price of the callipers was £90 each, indicating that they are not Toyota so the tolerances may not be as good as Toyota, so maybe they need greasing?

I will be visiting the area where the callipers were fitted in about two weeks, so I would rather visit personally than phone.

[oldcodger]

Hi,

Thats interesting that you have never greased any brake parts on any car, I've always always understood you needed to, but if you do not get any problems then why change.

I've mostly used Ferrodo pads and always have good wear and performance, and until I replaced the front calipers pistons and seals never had any problems, though now do suffer from pad rattle when going over bumps.

Tried various fixed but to only thing that worked was using CeraTec instead of copper grease.

The Mintex Cera Tec is a clearish pale yellow / green colour so it sounds like that or some similar product has been used.

Think if you get some onto you finger and compare it to actual grease to will see a distinct difference, its more  smoother and gel like than grease.

As far as I know copper grease  or cera tec is just used to stop pad chatter / etc, as mentioned,  many pads have a rubber backing to do the same, as do the shims fitted on the front brakes.

I usually buy the monthly Car Mechanics magazine and apart from an interesting read they do special features and  did one on brakes, am sure they show they used copper grease.

If you want to revert to a 'dry' system, you just need a spay can of brake cleaner  and some clean  cloths etc  ( cheap at ECP or Toolstation).

If they start to give any chatter/rattle, you know what to use.

[mickburkesnr]

When I change the brake pads I never used to grease the pads up. I've never noticed a squeal or anything either.

I did try and change brake pads on a CR-V once and I fluffed it, leading to air in the brake lines. Took it to this brake specialist who was recommended (old school type of chap, only worked 2 days a week) and he took it in and sorted it for me. But he greased everything, and I mean everything. The back of the pads, the calipers etc. Everything but the friction side of the pad and disc. Never understood the reason behind greasing the actual outside of the calipers though?

I'd be inclined to grease the back of the pads, only for the reason the grease isn't expensive and it doesn't harm anything. I look at it as much as a belt and braces approach to the job, so it doesn't have to be done but it's nice if it is.

[Notoyboy]

With all the disc braked cars I've owned, I've applied a small smear of copaslip grease to the area of the rear of the pads where the pistons are in contact. I also clean the pads' lugs where they locate in the caliper, and again, apply just a smear.  As much as anything, particularly in the case of the pads' lugs, the grease keeps the corrosion at bay.