Replacing Wheel Cylinder: Parts to have ready?

[SteveKuhn]

I need to replace the curb side, rear tandem wheel cylinder. I don't want to be delayed waiting for parts this time of year. I've read through the TMs for the procedure and I have a brake line hose, DOT5 & a cylinder. However, I figure I need at least the following on hand for recommended replacement or unexpected breakage:

• axle gasket (replace per TM)
• brake shoes (in case mine are soaked; I'll clean 'em later.)

What else? (springs, clips, etc.) What would you want to have handy in a box just in case? I'll probably need to do others before too long so I'd like to have spare parts.

Looks like I'll either be trying to find a gear lug wrench or buying a combo Budd socket.

Thanks.

Steve

 

[RAYZER]

Inner and outer seals and a wheel bearing set. I used rvt sealer instead of keyway gasket and flange gasket with good results.

 

[Clay James]

Don't forget, if you replace the brake pads you need to replace them on the other side too.

 

[WillWagner]

The banjo fitting gaskets. Eriks Surplus in San Diego has 'em. A hub nut socket. brake clean, grease, beer , friends...it's always more fun with others around!

 

[Keith_J]

NAPA carries the overhaul kits for wheel cylinders. Since all A2s have silicone brake fluid, corrosion is minimal in every one I have torn down. 30 seconds of honing and they are good as new with new boots, cups and a spring. All 5 pieces are in the kit.

The kits are superior to new old stock cylinders as the originals have plain ended springs which don't seal all that well. The kits have cup expanders which stop the annoying wheel cylinder leaks.

 

[Tow4]

Seals yes, you shouldn't need a bearing set. They get kind of pricey, I would check them first. Look at the race/cup, it will show wear first. If you see little pits missing, then get a bearing set. Otherwise just clean and repack.

You can use RTV instead of the cork for the keyway. Put a big glob on there to make sure it seals.

Spray the shoes down with gasoline to get the oil off. Brake cleaner works good too.

Look at the adjusters and note how they work. It will make it easier to adjust them latter.

You should probably change all the flexible brake lines. Glad I did.

I would check all the wheel cylinders. Even the ones that aren't leaking. All of mine were cruded up so bad that most had only one piston that was actually working. They were also pitted too bad to hone out, so I ended up replacing them all. If you go the new wheel cylinder route, they will come with the banjo gasket. If you have to, you can wipe the banjo gasket off and turn them over; I've never had one leak doing that.

Just a thought, if you end up doing all the wheel cylinders, consider changing to Dot3. After seeing the condition my wheel cylinders were in, I thought it would be better to use Dot3 so the water that gets into the system does not end up settling into the wheel cylinders. In a nut shell, Dot3 absorbs water so it stays suspended; Dot5 does not so it settles to the lowest point. Something to think about.

 

[Keith_J]

Yes, DOT 3 will absorb humidity. If you don't change it every two years, it will eventually saturate, then the water will drop out of solution and end up in the lowest spot causing corrosion. DOT 5 is far more resistant to humidity than DOT 3 or 4. Trust me on this, I've been wrenching brakes for nearly 30 years and every vehicle over 10 years old that never had brake fluid flushing needed work EXCEPT for those using silicone.

The best cleaning fluid for silicone-soaked friction surfaces is methylene chloride. Petroleum solvents work well enough if they evaporate fully. The only gasoline I would trust would be white gas, paint thinner is far safer and stinks less. Xylene and toluene are also good but with stronger smell.

 

[SteveKuhn]

These are very good replies. I am sticking w/ DOT5. I didn't realize that NAPA had the rebuild kits. I'll check there for some add'l things. Somewhere there's a crossreference . . .

I'm just lost on gasket terminology: 'Banjo'? 'Keyway'? Couldn't find them in the TMs and Google images weren't much help. I'll try going over the drawings again.

Thanks to all.

Steve

 

[Tow4]

I've been wrenching brakes for nearly 30 years

Me too. I'm not arguing which fluid is better. I'm explaining why I changed my truck to Dot3 and why I think it's better for this particular application based on my personal experience and observations.

Simply put; it's pretty obvious that moisture still gets into the system with Dot5. There are lots of "no brakes" threads, and not all of those vehicles were abused; mostly they just sat. My thought is it's better to use Dot3 and keep the moisture suspended and then flush it out every couple of years. The moisture sitting in the wheel cylinders in a Dot5 system is much heavier than the silicone and separated from it. I don't think it's going to be easy to flush it out.

Steve, a banjo bolt is hollow and designed to pass fluid and the washer is usually metal. I think the washer or gasket for this application is copper or brass. The banjo bolt fastens the brake line to the wheel cylinder.

The keyway is where the outside seal and hub nut lock tabs key to keep from rotating. Look on the diagram where the hub nuts thread onto the axle housing; it's the slot in the threads. You have to seal the keyway so grease/gear oil doesn't get into the brakes. It's all in the TM. Once you take it apart it will be obvious.

 

[Keith_J]

EVERY "no-brake" issue I have encountered with M35A2s has been due to inferior wheel cylinders which use the cylindrical springs without cup expanders. The cups fail to seal, brake fluid fills the area between the boots and cups, causing the pistons and shoes to retract.

Every instance was cured with aftermarket rebuild kits that utilize cup expanders on the ends of the springs. Every other vehicle using drum brakes uses cup expanders on the springs WITH glycol-based brake fluid.

The issue is bleeding brakes, glycol fluids (DOT 2-4) WILL absorb water but this capacity isn't infinite, drop the temperature a few degrees and water will come out of solution. On an infrequently used vehicle, I trust silicone over glycol any day. Silicone will not absorb water like glycol.

Even if you flush the system every 2 years, you still will have water settling in the cylinders. The cylinders have to be removed and cleaned as they are a trap if you are only using the bleeder screws to drain the system.

 

[SteveKuhn]

OK: Now the gasket names make sense. I found them. Thanks.

Steve

 

[chad650xt]

does anyone have the napa p/n for the cylinder rebuild kits? Thanks

 

[hndrsonj]

does anyone have the napa p/n for the cylinder rebuild kits? Thanks

https://docs.google.com/spreadsheet/ccc?key=0AoJuiPMjMpsVdEZxUEc2WlFuUHY5MlloS2VMYXlTQlE#gid=0

This is from the sticky in the deuce forum.

 

[Tlauden]

It's not hard, just time consuming.... And make sure you have a buddy to bleed the system when it's done, or make a power bleeder

 

[JasonS]

https://docs.google.com/spreadsheet/ccc?key=0AoJuiPMjMpsVdEZxUEc2WlFuUHY5MlloS2VMYXlTQlE#gid=0

This is from the sticky in the deuce forum.

and these have the cup expanders?

 

[SteveKuhn]

I just had my spare cyl put on and called NAPA for a rebuild kit and a new one. I was surprised when I learned that the kit was $13; the new part $30. I had seen a post saying that the kit was $5.

I ordered both, never the less. I have 5 others sitting out there that could need replacement at any time and I don't want to be without parts.

Steve