Wheel cylinder keeps blowing out on one side

You have too much travel for the wheel cylinder, breaks are not adjusted. Adjust the rear break shoes up to the drum so they are just dragging against the drums.

Did that but it still keeps blowing out on one side

Then check the E-break spreader bar, it could holding the shoes open. Push in on the shoes both sides at the wheel cylinder, The radius cut outs in the top of each shoe seats into the center round post at the top. Then you adjust them.

Okay I tried that put it all back together bleed the breaks and tested em and when I started the car and pumped the breaks a few times the seal blew again. Its a new wheel cylinder as well. Any other suggestions?

Does it feel like a good break pedal before this happens? If by chance the wheel cylinder is not defective, it is possible the proportional valve may be messed up. This regulates the pressure going to the rear wheel cylinders. There could be too much pressure for the wheel cylinder.

When the wheel cylinder is blowing, does the piston come out?

Yea the piston comes out.

Wow this one is tough, even if the proportional valve is messed up the piston should not have enough room to get pop out, As mentioned earlier check for proper adjustment and is the same side always blowing out?? check the brake shoe to see where the shoe and wheel cylinder meet they are connecting properly and the surfaces are flat.

The grand am I believe have two sizes wheel cylinders and shoes, just something else to look at

Yea its the same side every time.

Hello there Steven, hope everything is ok.

I was looking up parts for this, Not 2 different sizes for this one. Possible they boxed up the wrong one? Wrong wheel cylinder? There is no way that piston could come out if the shoes are together at the top post, and all the way in on the star adjuster, and the E-break is not holding it up. Compare it to the other side.

Alright thank you ill try that.

I doubt this is the problem but make sure the brake drum is not worn excessively. In any case the cause is excessive piston travel. You may want to replace the other brake hardware while you are at it.

Hey Rowefast, all is good on this side of the world, Hope you had good holidays, This is a odd problem, one I would like to see for myself, one wheel cylinder on one side blowing out. kinda rules out most possibilities and probabilities but none the less its still happening. How many times has this happened on the same wheel cylinder on the same side? We all can agree that this is a piston over travel problem but if the drum is not over sized, the correct wheel cylinder, shoes properly adjusted, ebrake lever in the proper position this can not happen.

Right, Should request a good picture to post so we can see it. I say the shoes are not together and adjusted wright, You know, I bet this guy is dealing with worn out shoes and drums, and trying to fix a wheel cylinder problem. This would cause over-travel of the piston..

Where are my manors, Hey there Steven B, all is good.

I had the same problem and on inspection I found the return spring on the bottom of the shoe unhooked and the shoe had slipped behind the stop allowing the shoe expand too far and the piston to pop out

I can not believe hearing "it can't happen" over and over. It happened to me 7x already. One wheel cylinder, repaced twice.

The adjuster bar has one side with 2 slots. The wider slot is installed inboard for the shoe cutout.

I have the same issue on my 2005 town and country , any other ideas? When I replaced mine it lasted for about a month then it blew out again.

I just boa 2008 jeep patriot and have the same problem I've went through 5 or 6 wheel cylinders yesterday and I can not figure out why please help

I had a Ford Tempo that happened to. The star wheel is NOT on the bottom (to spread the shoes out) but rather on the TOP, which causes the wheel cylinder to extend farther with lining wear. Because there was so much meat left of the linings, I tack welded a shim on the bottoms of the shoes (to simulate a 'bottom star wheel' spreading the shoes. Problem went away immediately. Engineering a star wheel at the top of the shoe is WRONG and it CAUSES the piston to come out of its bore (of course, after the warranty is over).

Hey Andrew, same thing is happening to me on my 08 hhr, you ever figure it out?

Found out what my problem was, hopefully it can help someone out. The pad that has the parking brake spring attached was not positioned correctly on the bottom. Looked good from the top, but on the bottom it needs to go against a stopper (for lack of a better term)