Very odd rear brake problem

1945 - 196*, Willys CJ series, questions, discussions, regarding anything related to the post war jeep.®
Bob Bell
G-Staff Sergeant
G-Staff Sergeant
Posts: 74
Joined: Tue Oct 21, 2003 6:01 pm
Location: Oakland, CA

Re: Very odd rear brake problem

Post by Bob Bell » Mon Nov 13, 2017 2:28 pm

Look again at your backing plate, they have short 1" raised pads either side of the wheel cylinders that the shoes rub against.

I know the pads that Ben Dover is talking about from other vehicles. However they are not present on either of the rear backing plates on this jeep. The only pads are the ones midway on the shoes that the two guidance 'forks' are attached to.
Bob Bell

1946 CJ2A

Ben Dover
Gee Addict
Posts: 40779
Joined: Sun Mar 02, 2008 2:37 pm
Location: Proving Ground

Re: Very odd rear brake problem

Post by Ben Dover » Tue Nov 14, 2017 4:55 am

And I may be off an inch or two. :wink: Some of the Jeep backing plates do have those pads.
Last edited by Ben Dover on Wed Nov 15, 2017 1:31 pm, edited 1 time in total.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

fiveftsix
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 464
Joined: Thu Dec 27, 2012 7:37 pm
Location: Kissimmee FL

Re: Very odd rear brake problem

Post by fiveftsix » Tue Nov 14, 2017 6:00 pm

I`d still check out that bearing while the hub and drum was off
Which you obviously haven`t done yet
4. The bearings are well greased.
5. I have NOT checked the backing plate for tightness, and will do so.
You can`t see that bearing and there is only one until you undo the backing plate bolts and remove the grease slinger etc
if the inner seal isn`t doing it`s job you could well be pumping grease down the axle tube
It can`t be a sticky cylinder now you implied you had changed it in a previous post
Geoff Bull

Ben Dover
Gee Addict
Posts: 40779
Joined: Sun Mar 02, 2008 2:37 pm
Location: Proving Ground

Re: Very odd rear brake problem

Post by Ben Dover » Wed Nov 15, 2017 5:21 am

I use a 5/8" Slide Hammer that has a Deep Nut that matches the thread on the slide hammer and welded another Deep Nut that matches the thread in the axle. Three whacks and the axle is out. The rear wheel bearings on CJ's, and M-38/M-38A1 are the most ignored bearings on Jeeps. Chances are your inner seals are worn and the wheel bearing that is pressed on the axle shaft has a good chance of being corroded and pitted.
Last edited by Ben Dover on Wed Nov 15, 2017 1:38 pm, edited 1 time in total.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

Bob Bell
G-Staff Sergeant
G-Staff Sergeant
Posts: 74
Joined: Tue Oct 21, 2003 6:01 pm
Location: Oakland, CA

Re: Very odd rear brake problem

Post by Bob Bell » Wed Nov 15, 2017 9:50 am

When I said the bearings are well greased, that is what I meant. No, I haven't pulled the axle shaft and inspected the bearing itself, BUT when I changed the seal I was able to see that it was well greased (plus I gave it a couple of squirts with the grease gun while I was at it).

So is the suggestion here that the bearing itself is causing the initial squeal?

I actually fabricated a tool for pulling the axle shaft earlier this year, as I am working on a 1951 3A, a frame up rebuild. I have completely rebuilt the trans, transfer, overdrive, front and real axles, so I am aware of the wear that can occur in these neglected areas.

And I agree that it is likely / possible that the inner seal is bad. However I keep a very close eye on the rear diff, and have not had to add oil. Also, each time I remove the brake drum, I do not see contamination.

I have driven the vehicle probably about 50 miles since the last time I took the drum off, sanded the linings etc. The squeal is still there, although it does go away pretty quickly. Initially, while the squeal is there, that wheel DOES lock up first. So sticky cylinder AGAIN???

Once brakes have been applied a couple of times, the vehicle stops well, quickly, and in a straight line. Sometimes quietly, sometimes not.
Bob Bell

1946 CJ2A


Ben Dover
Gee Addict
Posts: 40779
Joined: Sun Mar 02, 2008 2:37 pm
Location: Proving Ground

Re: Very odd rear brake problem

Post by Ben Dover » Wed Nov 15, 2017 1:29 pm

The Semi Floating Wheel Bearings run in grease(I use GAA), and are serviced via the grease fittings on the rear axle tubes next to the backing plates.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

fiveftsix
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 464
Joined: Thu Dec 27, 2012 7:37 pm
Location: Kissimmee FL

Re: Very odd rear brake problem

Post by fiveftsix » Wed Nov 15, 2017 5:35 pm

Bob, you seem to have checked the wheel cylinder several times as have you the shoes and back plate etc.
that doesn`t leave much else it could be that`s causing this squeal
And if you already have the hub and drum off your already 3/4 the way there anyway
So why not just pull the shaft ,wash off the bearing and inspect it thoroughly as well as spinning it by hand for roughness
I`d renew the inner seal too at the same time.
Even if the inner seal is not doing it`s job it`s quite possible the grease you`ve pumped in is preventing a great loss of Diff oil
But just enough is giving a slight lub to the bearing.
It could be squealing by the shaft rubbing either the seal or the metal slinger when weight is transferring when braking
Or the bearing itself causing it.
You may not see any contamination Bob as that would be caught by the outer grease slinger and will only be revealed once it`s off
But whatever it should be checked out only if to eliminate it from the equation !!!
Geoff Bull

Post Reply

Return to “CJ Technical Knowledge Base”

Who is online

Users browsing this forum: No registered users and 1 guest