Brake Slide Pins Galling, automotive

[fishrdan]

On my 2001 Honda Accord, the drivers side brake caliper has the nasty habit of sticking the caliper and then warping the rotor. Every time I remove that caliper the slide pins are locked up, but after a good hard shove it slides and then continues to slide freely, the caliper pins are galling and locking it into position, causing the rotor to warp. The passenger side caliper has never had a problem. I've cleaned and re-greased the slide pins with Sta-Lube synthetic caliper grease every time I've had the brakes apart, but the pin keeps galling and sticking.

I replace the pads and rotors a couple months ago and put about 5K miles on them. They were smooth as glass until and I was descending a couple of long grades at 75MPH, where I had to brake a lot. After a couple of steep grades I could feel the rotor pulsing,,, once again, and knew the stinkin pin had galled and stuck in place again.

I bought a new set of slide pins and a bottle of Permatex Ultra Disc Brake Caliper Lube Hi-Temp Silicone Formula as I heard Honda's were supposed to use a silicone based grease on the caliper pins. (The Permatex grease is a lot thicker and stickier than the old Sta-Lube grease.) I have a set of seals and will pull the caliper completely apart and replace all the seals, basically rebuild the caliper. That and a new set of rotor and pads, might as well do everything while I'm at it...

Do you think the Permatex caliper grease and new slide pins will keep the caliper pins from galling? Any tips or tricks?

 

[DECK SWABBER 58]

Re: Brake Slide Pins Galling, automotive

Not sure what seals you mean but make sure you replace the rubber boots that keep dirt and water out of the pins.

 

[Bob_VT]

Re: Brake Slide Pins Galling, automotive

You sure it is galling???? Those pins do not incur that pressure to gall. That pulsing could be rotor run out. Front brakes can be very easy to warp if you do not torque the front lugs and re-torque after a 100 or so miles. The rotors could be warped or just too thin...... depending on the pads you used they might have eaten the rotors fast.

Those pins just allow the pad to slide on and off and are just guides.

 

[fishrdan]

Re: Brake Slide Pins Galling, automotive

I'm replacing all the caliper piston and pin seals.

I'm pretty sure it's galling as the pins have worn away their dull machined surface so it's shiny now, shiny with some light pitting. Upon dissasembly the pin is stuck, giving the pin a hard bump will break the bond between the pin and housing and shove the pin into some fresh lube, then it will slide free again. When I replaced the brakes last time, the pins on the drivers caliper were stuck, even though the lube in the pins looked OK. I'm guessing the old lube doesn't have good film strength and wears off the pins, then they gall up. That's just my guess and the reason I posted up the question.

The rotors and pads were new. No excessive wear on the rotors, but the drivers side had some discoloration from getting hot after 5K miles, the discoloration is gone now, wiped off from driving around. The pulsing was from the rotor warping, after getting too hot. My take on the problem; the pins gall causing the caliper stick in place and not center on the rotor, then one pad rides too close to the rotor heating up that side and warping the rotor. I don't think the piston is hanging, though I'm going to check it.

My main concern is the pins getting stuck, (galling?). I think the old grease is the cause and wanted to see if anyone had seen this problem or had comments on the Permetex caliper grease.

 

[Thalasso]

Re: Brake Slide Pins Galling, automotive

That pulsating in the brakes is due to rotor warpage. The only way to correct it is to have them turned down if the can be turned. If not buy new ones. The slide pins on the calipers are not the problem. If the pads are binding on the pins or the pins are binding, because they do slide in and out, you have other problems. Buy a new caliper. Rebuilding them usually dosen't work well. GM had this problem back in the 90's on the pontiac granprix. If the slides are rusting it is do to water intrusion.

 

[DECK SWABBER 58]

Re: Brake Slide Pins Galling, automotive

I've used the Sta-Lube synthetic grease for years without any problems that I know of. In your case though, I would definately try the Permatex.

 

[BuzzStPoint]

Re: Brake Slide Pins Galling, automotive

Simply cleaning the pins may not help.

Clean the pins, and then use some emery cloth to remove any built up grease areas on the pin If you can get a stiff wire brush clean out the holes where the pin slides on the caliper.. Apply new grease.

 

[RogersJetboat454]

Re: Brake Slide Pins Galling, automotive

My vote is a new/reman caliper with the bracket. If the slides have ever rusted, you may be dealing with slide holes that are tapered or egg shaped, and the slide is getting jammed.

What some people may be failing to realize is these pads (if i remember correctly) are not attached to any sort of pin. They are held in place by the caliper bracket. The purpose of the slides is to allow the caliper to move so BOTH brake pads clamp EVENLY on the rotor. If the slides lock up, only the piston side pad will make contact. The outside pad will be hanging in the breeze. With just the piston side pad braking, additional force needs to be applied to the working pad in order to stop the vehicle. Overheating can occur, and rotor warping is entirely POSSIBLE.

 

[fishrdan]

Re: Brake Slide Pins Galling, automotive

get a stiff wire brush clean out the holes where the pin slides on the caliper..

I haven't cleaned the bracket holes before, but going to do that this time around. I bought new pins, so won't have to worry about cleaning them up.

If the slides have ever rusted.....

What some people may be failing to realize is these pads (if i remember correctly) are not attached to any sort of pin. They are held in place by the caliper bracket. The purpose of the slides is to allow the caliper to move so BOTH brake pads clamp EVENLY on the rotor.

I'm in the desert and have never seen any signs of rust on the pins, always fresh clean grease and a galled up pin. (No rust on the car anywhere either )

You are right about the mechanics of the caliper, the caliper floats on the pins, the pads rest on the bracket, letting the caliper and pads center over the rotor. Though, I think the pins locking up hold the outboard pad tight against the rotor, thus warping it. That or what you said about the inboard pad being held against the rotor. Either way, the pins are always locked up, warping the rotor......

I was going to get a rebuilt caliper, but everything to rebuild it cost $15, opposed to $60-70 for a complete rebuilt caliper and not knowing what kind of core they used.

 

[BuzzStPoint]

Re: Brake Slide Pins Galling, automotive

I haven't cleaned the bracket holes before, but going to do that this time around. I bought new pins, so won't have to worry about cleaning them up.

every caliper and bracket are different.. Cleaning the holes, let say a GM/Chevy style car, Many of these will have pins/bolts holding the caliper on. The caliper should slide on the pins. Cleaning out the slide area on the caliper so there is nothing in there would help. Then apply freash grease...

Can't tell you how many DIY'ers I have seen just slap new pads on, only to do it in 8 months to a year later.. Many times it's because of this sliding issue.
If you like working on cars and don't mind doing it, many will say just buy new/reman calipers and pins and be done with it.. If it's cheaper to do so, then by all means do that. but if it will cost you 2 bucks at the dollar store for some emery cloth and a stiff hole brush... spend 5 minutes and clean them.

I'm not into the whole "Replace" deal when working on cars. We need to get back to the days of fix it if it can be fixed.
I had a 78 chev pickup. A whole sprung in the radiator Almost dead center in the fins. Took it to a radiator place and they told me 300 some bucks to fix. Called the junk yard and they wanted 100 bucks for a used one... 4 dollars later I bought some rosin core solder and used my propane torch. Drove that truck to the junk yard 6 years later... Radiator still holding strong.

Fix it if you can is my vote.

 

[fishrdan]

Re: Brake Slide Pins Galling, automotive

Oh yeah, I'm the type that will fix it if I can. I just got through rebuilding the car's transmission a couple months ago. (stinkin' Honda automatic transmission,,, don't get me going on that one )

the caliper floats on the pins, the pads rest on the bracket, letting the caliper and pads center over the rotor.

Just for clarification, I didn't say that right... The pins are bolted to the caliper, with holes in the bracket, allows the caliper to slide over the bracket.

 

[stackz]

Re: Brake Slide Pins Galling, automotive

I'm gonna go with everyone else. replace the caliper. sounds like the caliper piston is freezing into place.

you ever fully flushed your brake lines?? the WHOLE system? how miles on the car if you havent?

brake fluid is just like any other hydraulic fluid. it will break down over time. first, it'll turn brown, then blackish. then the deposits start to form.

they are probably all built up on the inside of the caliper piston causing it to freeze in place and letting the pad rub the rotor until it warps.

then you beat on it and loosen everything up real quick and place the blame on the pins. the pins are under stress due to the piston being locked in the engaged position.

 

[fishrdan]

Re: Brake Slide Pins Galling, automotive

then you beat on it and loosen everything up real quick and place the blame on the pins. the pins are under stress due to the piston being locked in the engaged position.

Or the other way around, the outboard side of the rotor gets discolored from over heating, the inboard (piston) side of the rotor does not get discolored. Guess I'll find out if the piston is sticking when I tear the caliper apart this weekend.

Oh yeah, about 100K miles, never flushed the brakes,,, until this weekend...

 

[NetDoc]

Re: Brake Slide Pins Galling, automotive

Its my humble opinion that Honda's only weak point are their brakes. I have had some incredible luck with my 2006 Ridgeline. 184,000+ miles and I have replaced the front brakes at least a half dozen times and the rear brakes twice and its time to do the rears again. I have never turned my rotors, but replaced them on the last job. As a certified master technician, I would ask if the wear is different left to right.

The best part about calipers is that they reduce pedal travel significantly unless there is excessive run out on the rotor(s). The square cut caliper seals deflect out towards the bad when the brakes are applied and pull back when pressure is released. While pin cleanliness and alignment are critical, its common for the outside pads to wear quicker. Performance brakes get around this by having both inboard and outboard pistons.

BTW, a glassy finish is BAD for a rotor. A satin finish is awesome, but a shiny one requires a lot more force to stop which generates a lot more heat and will warp your rotors in a heartbeat.