Wheel cylinders

ELBUFO · Post by **ELBUFO** » Tue Feb 19, 2008 7:34 pm

Ok my new wheel cylinders arrived. For the life of me I don't see the difference between right and left. The boxes they came in have different part numbers, but that's the only difference I can see. I haven't tore into the "M" yet to compare against the old ones. I read that there was an old style and a new style, but don't know what the change was.so.... what is the real deal???
Thanks...John

Nickathome · Post by **Nickathome** » Wed Feb 20, 2008 3:31 am

I had the same problem when I bought mine. They are supposed to(if not mistaken) have an L or an R stamped on them. If not, the only way I know to tell is to pull the rubber cups off and check the piston sizes. Each cylinder has one large piston and one smaller one. I think, I say I think the larger piston is supposed to face front(Its been a while since I replaced mine). So if you place the cylinder in the upright position and check the piston size you will be able to tell which side they belong on. Someone else can back up or refute my claims about which sized piston belongs facing front. I think I am right though.

rixm37 · Post by **rixm37** » Wed Feb 20, 2008 6:39 am

This is taken from the brake service section of the manual printed by the Power Wagon Advertiser. It is a great book worth the money get it from the PWA website. The big bore goes to the rear. Also the part numbers are different. It is furhter recomended that you check each cyl to make sure it is assembled correctly and has all its parts. Also do not rebuild wheel cyls not worth it as pitting is the big problem and wont be eliminated by honing. and remeber your life depends on the brakes.

rixm37 · Post by **rixm37** » Wed Feb 20, 2008 6:48 am

Here is a little more info same book:
"The stepped wheel has two different bore diameters and two sizes of pistons. The big piston yeilds more force because it has more surface area. The big piston goes to the rear of the brake.
The truck goes forward most of the time, and when it does the forward shoe will self engergize. The rear shoe will not. The rear shoe needs help in the development of braking power. It revieves this help in the form of the larger piston diameter. It allows the shoe to be pushed against the drum with more force."
Hope this helps

rixm37 · Post by **rixm37** » Wed Feb 20, 2008 6:51 am

THE STEPPED WHEEL CYLINDER I gotta do better on my self editing
Sorry

Nickathome · Post by **Nickathome** » Wed Feb 20, 2008 9:40 am

Damn, I had a fifty fifty chance and blew it. Sorry about that but again its been over a year since I did my brakes and I simply forgot the position of the large piston. I would go with that rixm37 mentions from the book. Big piston to the rear. I'm glad someone chimed in to correct me.

ELBUFO · Post by **ELBUFO** » Wed Feb 20, 2008 10:17 am

Stepped wheel cylinders. I would have never guessed it. I have been turning wrenches for years...20 of them professionally in the USAF...First time I have ever ran into this...Makes sense though as the rest of the brake system is primitive..Neat way to get the extra umph to the back brake shoe. I have to say the "M" is an interesting beastie Thanks for the input...John

Wheel cylinders

Wheel cylinders

Wheel cylinders

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