90 Comanche rear drum brakes (again)

[pioneerpilot]

Howdy

I have a 90 Comanche 4WD, 4.0 , Pioneer.

I have been having trouble , (lots) withthe rear brakes. I replaced the booster, master cylinder, rear brakes , a couple of lines. The pedal goes right to the floor. I have brakes , but right at the last 1 inch of pedal travel.

Now,, I noticed in the factory manual it shows two studs, (rods) coming from the end of the wheel cylinder ( someithing like the old Chevies had) to the web of the brakes shoe. These are on the 9inch brakes. The 10 inch brakes do not have them. Mine are missing. My question? Do I need these studs to make the rear brakes operate or have they been done away ?

This is driving me crazy....

Thanks , Pioneerpilot

[Wildman]

Are you saying you don't have the push rods from the wheel cylinder to the brake shoes???

 

:eek:

 

If that's the case, there's your problem..........don't matter if it a chevy, ford or what ever, all drum brakes, with wheel cylinders need the push rods to the shoes.

 

When you buy new wheel cylinders, the push rods don't come with them, you buy new one separate, or re-use your old ones.

 

Here.......take a gander at this -

 

http://www.familycar.com/brakes.htm

 

Question back at ya, do you still have the load sensing valve in the rear brake lines????

[Eagle]

My question? Do I need these studs to make the rear brakes operate or have they been done away ?

You need them.

[Geonovast]

:hmm:

 

I have 3 Jeeps with the 9 inch brakes. I've never seen a single push rod from the cylinder to the shoe, a tab on the shoe just sits in a cup on the cylinder.

 

 

[Wildman]

OK.......that's new to me :hmm: plus, I don't have anything with 9" brakes.......at least taken apart.

 

And if Geonovast said there not needed, then I'll believe it ;)

 

So........could the OP possibility have the wrong shoes :dunno:

 

The way he wrote, it sounds like the wheel cylinders are bottoming out, over expanding, and that's why his foot pedal it almost to the floor before he gets resistances.

 

Guest we'll find out........if he remembers to stop back in here :roll:

[juan]

I have done rear brakes on many of my jeeps and my brakes do have the short stem metal rod that goes from the wheel cyl to the shoe. As a matter of fact a few days back a completly re did the rear shoes in my 87 xj including new whell cyl. The new whell cyl did not come with new stem rods - so I used my old ones, w/o these rods the wheel cyl will never work.

[Eagle]

I have done rear brakes on many of my jeeps and my brakes do have the short stem metal rod that goes from the wheel cyl to the shoe. As a matter of fact a few days back a completly re did the rear shoes in my 87 xj including new whell cyl. The new whell cyl did not come with new stem rods - so I used my old ones, w/o these rods the wheel cyl will never work.

But an '87 had the 10" drums. Chrysler switched to their 9" rear brakes beginning in 1990.

 

I don't have a 1990 FSM but I do have a '94. It shows several exploded views that don't show the wheel cylinders, so it's unclear if the push rods were omitted or not used. The view of a wheel cylinder mounted to the backing plate DOES show the push rods.

 

Ah! Another view, of the wheel cylinder assembly (only) for the 9" brakes shows something they call the "link," that seems to be the same as the push rod but looks like it has a threaded inner end to perhaps thread into the piston(?). Dunno - I haven't yet worked on one with the 9" brakes. Wheel cylinders are wheel cylinders. They do not include the push rods/links. Those usually come in the small parts kits that include the hold-down and return springs.

[Geonovast]

So the 'push rod link thing' on the 9" drums are possibly attached, and under the boot? I've never purchased a new cylinder, but I do have an 8.25 sitting around with a cylinder I can take apart tomorrow.

[danboone5]

Just did my rear brakes two weeks ago. Mine are the 10in drums also. You must have the push rods or they will not work. Mine had a blown wheel cylinder and were missing the push rods and the brake bar. Most of the parts on the 10in are the same as a does 10in. Push rods are I'm sure of. The brake bar I had to fab.the Dorman bar was just a little small. If you need any more info just send a PM.

[Geonovast]

Most of the parts on the 10in are the same as a does 10in. Push rods are I'm sure of.

 

You mean parts in the 10in are the same as the 9in?

 

Nooo. I don't think a single piece interchanges between the two.

[danboone5]

Sorry guys, I meant too type our 10in rear brakes share a lot of the same parts as 10in Ford rear brakes. A lot of Fords have the d44 rear. Just learned that at work last week from a Chrysler mechanic. So a lot of these misc. parts can be found if you look under a Ford 10in.

[pioneerpilot]

Howdy to all

Quite a response to my question about the 90 Com rear brakes.

I am going to work on it today. I do have the valve at the rear diff. also. I had to wait to get parts for that... I got them by the way at Reid Supply Co. ReidSupply.com. For 1/4-28 rod end it was a couple of bucks apiece.Rod ends are complete except nut for stud. Shipping : via usps. priority mail. The 1/4 -28 stainless steel rod I purchased at Servocity. Winfield , Ks. 3.15 for each rod.... Should work.

Very quick service from each Co....

:clapping:

I am going to the dealer on Wed.. I am taking the book with me. ( as I mentioned ,I have the factory overhaul manual) That;s where I first saw the pic of the rods(links)

Just about time to go to work... Again, thanks to all. I will keep ya'lll posted...

Pioneerpilot

[ParadiseMJ]

I did my first drum brake job in 1969 on my 64' Chevy pick-up. Since then I've done drum brakes on several VW's, a Pinto, 2 Ford trucks, a Volvo, 2 different Mercedes, a couple of other Chevys, a CJ, XJs (a 90 and a 92) both 9", Nissan Maxima and Sentra, Astro van, Mercury Villager and finally (2 weeks ago) my 88 MJ 10" brakes.

 

I have personally never seen a set of drum brakes without the push rods. Somehow I doubt that Chrysler and/or Jeep were innovators in eliminating this part and designing something simpler. I have never gotten the rods in a package, I've always reused the old ones whether I rebuilt the cylinders myself or bought new cylinders. There just isn't enough movement (travel) in the 2.5" wide cylinder to push a tab in the shoe far enough to make the brake effective. Also, why would there be a round hole in the cylinder for a rectangular "tab" on the shoe? Just doesn't make sense.

 

I'm not stupid enough to think that it can't be, or arrogant enough to think that I know it all...I'm just sayin'!

 

Did you adjust the brakes after you put the drum on? How well does your e-brake work?

[Geonovast]

I've replaced the pads on all three 9 in axles. Unless the push rod is attached to the cylinder and under the boot, the 9 in ones do not have them. All the brakes on all three Jeeps worked.

[aemsee]

I've replaced the pads on all three 9 in axles. Unless the push rod is attached to the cylinder and under the boot, the 9 in ones do not have them. All the brakes on all three Jeeps worked.

 

:agree: . Genovast is completely correct.

[Yesterday's Danish]

For what its worth, my 2000 XJ also doesn't have the push rods visible. It has a 8.25 Chrysler in the rear. Just press the tab of the brake shoe into the wheel cylinder and call it good.

[kastein]

I did my first drum brake job in 1969 on my 64' Chevy pick-up. Since then I've done drum brakes on several VW's, a Pinto, 2 Ford trucks, a Volvo, 2 different Mercedes, a couple of other Chevys, a CJ, XJs (a 90 and a 92) both 9", Nissan Maxima and Sentra, Astro van, Mercury Villager and finally (2 weeks ago) my 88 MJ 10" brakes.

 

I have personally never seen a set of drum brakes without the push rods. Somehow I doubt that Chrysler and/or Jeep were innovators in eliminating this part and designing something simpler. I have never gotten the rods in a package, I've always reused the old ones whether I rebuilt the cylinders myself or bought new cylinders. There just isn't enough movement (travel) in the 2.5" wide cylinder to push a tab in the shoe far enough to make the brake effective. Also, why would there be a round hole in the cylinder for a rectangular "tab" on the shoe? Just doesn't make sense.

 

I'm not stupid enough to think that it can't be, or arrogant enough to think that I know it all...I'm just sayin'!

 

Did you adjust the brakes after you put the drum on? How well does your e-brake work?

Just did the wheel cylinders on the d35 on my 91 Sunday. I think it's got 9" drums, didn't bother to measure, but it certainly did not have pushrods.

 

Wish I hadn't had to waste money throwing wheel cylinders on a 35 when I have an 8.25 going in soon, but I can't afford to do anything that might result in the MJ not being driveable as I have a move coming up in a week or two and it just has to hold together till then.

[Geonovast]

Wish I hadn't had to waste money throwing wheel cylinders on a 35 when I have an 8.25 going in soon, but I can't afford to do anything that might result in the MJ not being driveable as I have a move coming up in a week or two and it just has to hold together till then.

 

The 9 inch brakes on a D35 and 8.25 are the same.

[ParadiseMJ]

Well, shut my mouth. I guess I haven't done all and seen all. I better go back to school!!