fastsuv

One of my rear drum brake wheel cylinders had a problem which required me to remove the pistons. After the repair, I needed to bleed the brakes but the bleeder won't budge. It just strips away metal from the bleeder without turning due to the rust. So looks like I will be replacing the wheel cylinder

In all probability, the same will happen to the two screws holding the wheel cylinder to the backing plate. I can grind off the screw heads and remove the wheel cylinder (after removing the brake line), but I will need a couple of new screws. I can't find the screw size and length of those two screws. Does anyone know what size they are?

Thanks
Steve

donbrew

If you have a 2009-2011 the part # is 20785652.

2006-2008 is 22688717, discontinued for some reason.

I imagine they are the same, just different numbers, they changed rear brake design in 2009.

fastsuv

No dealer in the area has them in stock and it will take 3-5 days to gt them in.

I am going to see what happens when I take off the wheel cylinder. Checking the net, I found a post where the Saturn Ion owner said his bolts were M6-1.00 x 12mm. So I might be able to use some regular metric bolts from the hardware store. Then a post by a Cobalt owner said his bolts were E8 external torx head. This might be true because the bolts appear pretty close to the round part of the cylinder that extends through the backing plate, making it hard to fit a tool in there.

First, I will try to force the bleeder out and if I break it, so what I was going to replace it anyways.

Steve

sleeper

I like to spray any bolts/ nuts & /or bleeders a few days prior to the operation.

Gives my favorite: Kano Aero Kroil Penetrating Oil or whatever your choice of rust penetrant a chance to penetrate the rust.

And are you using a brake line wrench ? Regular wrench is not the same. You shouldn't be rounding of the bleeder nut.

SuKi

Aero Kroil, in my experience, is hands down the best penetrating oilon the market.

sleeper

Yes it really works.

fastsuv

I replaced the wheel cylinder.

The brake line came off pretty easily with a flare nut wrench.

The two bolts holding the wheel cylinder to the backing plate are E8 external Torx bolts. I bought a complete set of the E-sockets (8pc) from HF for $8 after the 20% off coupon. Using the socket, the bolts also came out easily.

After I replaced the wheel cylinder, I took the old one into my shop to see if the bleeder would come out. It was corroded to the cylinder and would not budge. The cylinder is aluminum and the bleeder is steel, so there is dissimilar-metal corrosion happening. There is little reason to bleed the brakes unless a wheel cylinder, caliper, or master cylinder is replaced (or a brake line/hose). However, if you wait too long it may not budge. For those of us in corrosive winter climates, it may be beneficial to move the bleeder every few years to keep it from fusing to the cylinder. Maybe another reason to change the brake fluid every 2-3 years or so.

Steve

donbrew

Flushing the brake fluid is definitely one of the optional service things I agree with. I don't know why it is not on the regular maintenance schedule.

sleeper

1st time I did a brake fluid flush & refill on my '08, I took out the bleeders & coated the threads in Anti-seize, haven't had issue doing it again after that.


Don- the Wife's Mopar has it listed as a maintenance service every 2 years.

donbrew

The list of flushes that shops use does include it. Our Owner Manual does no.

That list also recommends flushing the power steering fluid, and some dealership indeed charged for it.