The Stovebolt Site Forums The Shop Area General Truck Talk Stuck Wheel Cylinder

I've got the wheel cylinders off from the brake backing plate, but the pistons are stuck inside the cylinder.

I put it in the deep freeze overnight and that shrunk the aluminum piston enough that I could push them in further. How do I push the piston out though?

Any thoughts? Thanks.

Ditto that. I had to drive mine out.

Generally when they are stuck there is enough corrosion to eat into the casting and they probably won't clean up. New cylinders are cheap insurance. Fred

rfs56trk hit the nail on the head. But if you wish to o/h them ditto on Tiny's dotto.

Hey jhaa_lives, Have you ever been to the Blue Owl resturant in Kimswick MO.? My sis-inlaw ownes that. Good vittles.

Toyvo - No I've not... but I have been to Kimswick. Nice little day trip get away. Next time there I'll definitely check it out.

Everyone - OK... got to buck up and buy some cylinders. It's nice to know how to handle this if (in some future time) the cylinders are not available. It's always nice to know how to rehab instead of purchase new. Sort of my motto for the work on this truck.

Thanks all!

soak them good with penitrating oil, drive the pistons out as above. try a light honeing, and see if the cyl. can be saved. Some new cylenders are almost junk. Rinse the cyl with alcohal to remove any petroleum products before replacing the cups and pistons.

The wheel cylinders cleaned up nicely on my 38 even though I had to drive the pistons out. Buy yourself a wheel cylinder hone for $15 & try it. You might be surprised & save yourself some money too. I would at least see how they clean up before putting out the money on new ones.

If you are going to hone them, I take mine completely apart, bead blast them and then take them to a machine shop that has a sunnen "fixed" straight hone (not a flex hone). You could hone out .005-.006" safely. Then put a new kit in it.

Some of the new cylinders are cheap enough that it is cheaper to replace though.

Make sure you know what you are doing if you plan on honing them. Brakes are nothing to be guessing at.

wheel cylinders are made to accomodate some wear. Most shop manuals will tell you how much. To check wear put in the small solid cup and then slide a guage up in beside it. In most cases it should not be over .005 and if it is definitely replace the wheel cylinder. If the cylinder "looks" bad try honing it anyway. I have cleaned up many bad looking ones and still not be over .003 which is plenty good. As someone did mention you can just about buy the complete cylinder for just a couple bucks more than a kit would cost. Now if everything is looking OK you may even be able to just buy the cups and be find IF you can still find only the cups, It would also depend on how old or how deteriated the other pieces are. In plain english it depends on good common judgement and how deep your pockets are but safety should be first.

For what you would spend on a hone and rebuild kits you wouldtn't be too far off from the price of new wheel cylinders. In fact most times the complete cylinder is less than the rebuild kit. We never rebuild wheel cylinders or calipers at the shop for this reason. there is also less chance of failure due to pitting/out of round conditions. Find a parts house that carries Wagner brake parts, they are a division of Federal-Mogul and are top quality parts.

Longbox is right.
labor o/h 1 cyl. 1.0 hr.@ 60.00 = 60.00
parts kit $15.00
hone $15.00
total $90.00
If the cyl. won't o/h then you have .5 labor or $30.00, hone $15.00 (you used it), wheel cyl. 40.00 and install it. .5 and $30.00 also another $5.00 for trip to parts house. $120.00
If you replace it from the git go labor .8 hr. or 48.00 and a wheel cyl. at 40.00 totals 84.00

You can remove the pistons with a grease gun and do no damage to the cylinder pistons or spring. Any time I've ever beat on cylinders with a hammer nothing good ever come of it. If this is a old huck system they can be redone for about $3 a piece. Just clean the pistons and hone the cylinder clean. It's best to hone the cylinders in a drill press that you can get down to around 100 rpm most hand drills turn way to fast and leave a bad finish I've had very good luck with going as much as 7 or 8 thou over as long as it is honed to a fine finish. I'll put a properly redone oe cylinder against the whang chang imports any day. The last set of cylinders I did for a 52 chevy set me back about $6 and a nice quiet afternoon in the shop, still working great after 2 years. If you have trouble getting the bleeders lose I've got a fix for that to.

i found it much less $ for the kit than for the imported cyl. on my 39. The frozen cylinders cleaned up "like new".

Yeah, but why rebuild a questionable wheel cylinder when there are high quality USA made replacements available? I'll stick with using Wagner wheel cylinders over a cheap import part, be it complete assembly or overhaul parts, any day.

I rebuilt mine because new replacements are $75 a pop X 4. I've rebuilt cylinders for 40 years & never had one fail.

WOW, that's high for a wheel cylinder. I can see rebuilding them in that situation, if the castings aren't too bad. When I got the cylinders for the '55, they where only $28 apeice. And that was for US made parts, not imports.

Some wheel cylinders cost $10 for rebuilds. Some cost $75 on up. It all depends on how common they are.

It costs me $15 to $20 to have the machine shop hone all my master and wheels cylinders out for me. Another $20 to $30 for kits. My time is worth more if I don't spend the money and do the work myself than if I spend an extra $200 and watch TV with the time I save. Then I have another $200 to spend on some other goodies I can safely rebuild myself.

If I end up replacing the shoes, have the drums turned down and replace the hoses and a steel line or two, I can have the whole works done for $90 to $150, depending on who I know that day.

If you get to know the small shop guys (not Midas, or Mieneke) they will remember you if you bring the parts to an old truck in and tell them about your project. They start giving you the good guy discount, and they like it too.

The wheel cylinders for my '62 were really expensive. I bought a hone and rebuild kits for a fraction of the cost.
The stones on the hone just about covered the entire surface area of the cylinder, so I didn't worry about a hand held drill getting me an uneven bore. The flex hose would take up any misalignment, while the flat stones should keep themselves square in the bore.
Remember, you're dealing with aluminum pistons in there--aluminum corrodes, and aluminum oxide is very thick/furry, even though not much thickness is removed from the parent piece. That's probably why they're frozen.
For mine, I cleaned off the sides of the pistons with a very fine wire wheel in my bench grinder. For the face of the piston, I simply cleaned it off as well, and then layed it on the concrete floor, face down, and did nice even Figure 8s, cleaning off the face and making it relatively square. It's just fluid pushing against the face though, so I wasn't terribly concerned with a square face.
New seals, new bleaders, and attention to detail. Driven every single day for the last 6 months, a minimum of 25 miles to/from work every day (and 3/5 days a second round trip home for lunch), and I haven't had a single leaky cylinder or brake problem.
But I'm still saving for a dual reservoir/front disc kit!
-Brad

I know a lot of guys use them, but I still have a problem with the little brake hones you buy dowwn town. I would always use a "fixed" hone and a machinist.

Just my firm opinion.