New engine and citroen van

This is probably somewhat passe by now, but regarding brakes, this is my technique......
With the caliper bracket off and in the vice, I pop off the anti rattle shims / clips and investigate the metal beneath. If there is any rust there (nearly always is) its back down to bare metal by either wire brushing or careful filing. Rust expands at a phenomenal rate and any expansion there will grip the pads firmer than intentioned.
The caliper bracket is a drop forging and I've no idea what the metal constituents are - some rust like hell, others hardly mark and the make of vehicle doesn't seem to matter.
This done, its on with the ceramic grease and replace the rattle shims after wire brushing them clean. More ceramic grease on the pad edges and backs and then carefully reassembled, using silicone grease on the pad sliders and rubber boots if necessary.
I shift the bleed nipple and coat that too.
Even more ceramic grease is applied to the cleaned hub, and of course where the alloy wheel faces onto the disc.
Personally I think that coppaslip has had its day regarding braking systems.
John :)
 
For some reason I don't have to grease my brake parts. I take them off and put them back on. No problems. Could be that I don't use the brakes much to notice a problem. I did brush copper grease onto the back end shields for the discs. Copper colour is better looking than rust colour.
 
Burnerman said:
This is probably somewhat passe by now, but regarding brakes, this is my technique......
With the caliper bracket off and in the vice, I pop off the anti rattle shims / clips and investigate the metal beneath. If there is any rust there (nearly always is) its back down to bare metal by either wire brushing or careful filing. Rust expands at a phenomenal rate and any expansion there will grip the pads firmer than intentioned.
The caliper bracket is a drop forging and I've no idea what the metal constituents are - some rust like hell, others hardly mark and the make of vehicle doesn't seem to matter.
This done, its on with the ceramic grease and replace the rattle shims after wire brushing them clean. More ceramic grease on the pad edges and backs and then carefully reassembled, using silicone grease on the pad sliders and rubber boots if necessary.
I shift the bleed nipple and coat that too.
Even more ceramic grease is applied to the cleaned hub, and of course where the alloy wheel faces onto the disc.
Personally I think that coppaslip has had its day regarding braking systems.
John :)
Click to expand...

I wouldn't swear to it, but I think most "everyday" calipers are iron castings, rather than forgings? The shims are (and I really can't believe manufacturers do this!) stainless steel, so as soon as you put it in contact with something ferrous, it sets up a galvanic cell and starts rusting the iron underneath it! Years ago, when pads just ran in the cast iron, this was never a problem and I'm not sure why manufacturers started doing it? My best guess, is that years ago, cars weren't refined enough for people to hear the pads rattling? Anyway, I absolutely agree with your approach there. The rust needs to be brushed (or filed) off the caliper before you do anything else.
I prefer the ceramic to the silicone grease, but only because every tin of silicone grease I've ever had (well, steel tins, at least!) has rusted quite alarmingly. Not sure why that is, but it worries me!
 
Avocet said:
It's as good as anything for the backs of pads, because it sort of bakes-on, and forms a bit of anti-squeal damping. For slider pins, I used to find it went hard fairly quickly, and made them quite sticky, so I went over to ceramic grease, which seems to stay slippier for longer.
Click to expand...

My brakes last forever, and I don't mean I make much use of the gears to slow me down, rather I try my best to take my foot off the loud pedal in time to minimise the need to brake, in my normal driving.
 
Avocet said:
every tin of silicone grease I've ever had (well, steel tins, at least!) has rusted quite alarmingly.
Click to expand...
You probably bought the wrong stuff. The halford plastic tub of grease I have is good as new after 20 years. I probably used it a couple of times for house door and window.
 
Harry Bloomfield said:
My brakes last forever, and I don't mean I make much use of the gears to slow me down, rather I try my best to take my foot off the loud pedal in time to minimise the need to brake, in my normal driving.
Click to expand...
A mate at a mainstream manufacturer, who I spoke to a few months back, was telling me they were having problems with sticking calipers on their electric vehicles, simply because they got so little use, as a result of the regenerative braking. I think there's a happy medium when it comes to brake use. In general, I've found some of the quickest drivers to be the lightest on their brakes. On track days, it was usually the rookies who would come in after a few laps with their brakes absolutely "cooked". Any idiot can "gun it" down the straights and then stand on the brakes, just before the bend, but the better ones are much smoother, and carry their speed through the bends, so they're easier on the brakes.
 
DiyNutJob said:
You probably bought the wrong stuff. The halford plastic tub of grease I have is good as new after 20 years. I probably used it a couple of times for house door and window.
Click to expand...
It's true, plastic doesn't rust... well spotted... :rolleyes:
 
Avocet said:
I wouldn't swear to it, but I think most "everyday" calipers are iron castings, rather than forgings? The shims are (and I really can't believe manufacturers do this!) stainless steel, so as soon as you put it in contact with something ferrous, it sets up a galvanic cell and starts rusting the iron underneath it! Years ago, when pads just ran in the cast iron, this was never a problem and I'm not sure why manufacturers started doing it? My best guess, is that years ago, cars weren't refined enough for people to hear the pads rattling? Anyway, I absolutely agree with your approach there. The rust needs to be brushed (or filed) off the caliper before you do anything else.
I prefer the ceramic to the silicone grease, but only because every tin of silicone grease I've ever had (well, steel tins, at least!) has rusted quite alarmingly. Not sure why that is, but it worries me!
Click to expand...
Aye, you may be right.....for sure the bracket is as tough as hell, I once saw once bent nearly double without snapping - hence my assumption.
John :)
 
Avocet said:
A mate at a mainstream manufacturer, who I spoke to a few months back, was telling me they were having problems with sticking calipers on their electric vehicles, simply because they got so little use, as a result of the regenerative braking. I think there's a happy medium when it comes to brake use. In general, I've found some of the quickest drivers to be the lightest on their brakes. On track days, it was usually the rookies who would come in after a few laps with their brakes absolutely "cooked". Any idiot can "gun it" down the straights and then stand on the brakes, just before the bend, but the better ones are much smoother, and carry their speed through the bends, so they're easier on the brakes.
Click to expand...
I assume electric vehicles will have some sort of electrical assistance, as there isn't any brake servo? Certainly on the heavier cars it could be necessary. Maybe the pad material is different too - I really wouldn't know.
John :)
 
Harry Bloomfield said:
My brakes last forever, and I don't mean I make much use of the gears to slow me down, rather I try my best to take my foot off the loud pedal in time to minimise the need to brake, in my normal driving.
Click to expand...
I think I often manage whole journeys without touching the brakes above 10mph, thats how I get 60 mpg. Also the brakes never wear out. Have to try and remember to give them a quick warm up before stopping an a wet day (leaves them dry)
 
Burnerman said:
I assume electric vehicles will have some sort of electrical assistance, as there isn't any brake servo? Certainly on the heavier cars it could be necessary. Maybe the pad material is different too - I really wouldn't know.
John :)
Click to expand...

Some grades of cast iron can be incredibly ductile, but I'm only guessing at castings. They could well be forged.

EVs usually have an electrically driven vacuum pump for the brake servo. In fact, more internal combustion engined cars than I would have imagined, also use an electric vacuum pump!
 
Burnerman said:
I assume electric vehicles will have some sort of electrical assistance, as there isn't any brake servo? Certainly on the heavier cars it could be necessary. Maybe the pad material is different too - I really wouldn't know.
Click to expand...

Don't some cars use electric servos in place of vacuum?
 
Avocet said:
EVs usually have an electrically driven vacuum pump for the brake servo. In fact, more internal combustion engined cars than I would have imagined, also use an electric vacuum pump!
Click to expand...

My diesel uses one - diesels do not generate any vacuum on the air intake.
 
You must log in or register to reply here.
Back
Top