brake cylinders

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QuackAxel

QuackAxel

10 Year
Joined
May 17, 2011
Threads
52
Messages
538
Location
Corvallis, MT
ok im sure this information is somewhere on the web but iv looked for a while and cant find it. i need to replace my wheel cylinders on my 40. just the rear as the front are discs. all the websites say that all for rear cylinders are different??? is this correct? visually they look the same, ones adjuster up and ones adjuster down, and the bleeder screw is on the opposite side. am i missing something? are there 4 different part numbers for the four rear cylinders? or will just one part number work for all four? this is on a 10/72 fj40.

thanks in advance.
 
As I recall, to do it right there are 4 different clys for the back axle.

If you had to do a field repair you could fit any Cly in any location BUT and it's a big but, the adjuster stars would be in the wrong orientation. It would be a major pain to remember which was which when you turn the adjuster to tighten or loosen.

With 4 correct clys you always turn all the adjusters one way to loosen and the other way to tighten, both back wheels and all 4 clys.

John
 
Iv priced this and napa wants 275 for all four and shoes. But to convert to disk is right at 325 but I have access to a junkyard that I can get the s10 calipers that I can turn in for cores and mine drops to 305 and if I get lucky and the pads look new I'll only have 285 in my swap so for me it doesn't pay to go back drum over disk when is 10-20$ difference. And I don't have to adjust any more Get intouch with poser for parts I ordered mine today
 
What about using front cylinders on the rear. I only ask because I'm selling my 40 soon and don't want to spend a tin on it right now. I have my old drums off the front of my 40 and could use those cylinders. Any thoughts?


...via IH8MUD app
 
I'm in the midst of replacing all the wheel cylinders on my '73 FJ40, so I've become quite familiar with the wheel cylinder differences.

First, this applies to front cylinders for FJ40 models 9/71 - 9/75 and rear cylinders for FJ40 models 9/71 - 7/80, stock configurations. I don't know about FJ45's or FJ55's.

REAR
Rear wheel cylinders do indeed consist of four different items, all four with 7/8" bore diameters. The driver's side (Left) front and rear wheel cylinders both have right hand thread adjusters. The passenger's side (Right) both have left hand thread adjusters. Both left and right FRONT wheel cylinders have two ports, one port for the bleeder screw, the second port for the brake tube jumper supply line from the REAR cylinder in the same location. Both left and right REAR wheel cylinders have two ports, one for the jumper tube to the FRONT cylinder, the second for the brake tube supply line coming off of the rear axle housing.

Summary:
Rear Left Front (RLF): Right Hand Thread, bleeder, tube
Rear Left Rear (RLR): Right Hand Thread, tube, tube
Rear Right Front (RRF): Left Hand Thread, bleeder, tube
Rear Right Rear (RRR): Left Hand Thread, tube, tube

Special note: the jumper brake tube between the front and rear wheel cylinders is still available from Toyota for about $8 - 9 each. With the tight radius near the ends, this is a bargain. Beno was able to get them for me.

FRONT
Front wheel cylinders are easier. There are two different styles of front wheel cylinders, one style for the Driver's side, the other style for the passenger's side. All four have 1 1/4" bore diameters. Once again, Driver's side cylinder adjusters are RH thread, Passenger's side are LH thread. As noted above, wheel cylinders for the same wheel are identical.

Summary:
Front Left Front (FLF): Right Hand Thread, bleeder, tube; same as FLR
Front Left Rear (FLR): Right Hand Thread, bleeder, tube; same as FLF
Front Right Front (FRF): Left Hand Thread, bleeder, tube; same as FRR
Front Right Rear (FRR): Left Hand Thread, bleeder, tube; same as FRF

Other issues:

The 'slots' on the OEM wheel cylinders that the brake shoes fit into are 'indexed' so the brake shoes may only be mounted in one direction. The adjuster-end slot is wider to accommodate the 'wide' footed end of the brake shoe, while the opposite end of the same wheel cylinder is narrower to only accept the 'narrow' footed end of the brake shoe. Many of the aftermarket wheel cylinders (from painful, personal experience) may not have the wide slot. The 'solution' is seek out the correct wheel cylinders with wide slots, or salvage the wide-slotted adjusters from the OEM cylinders for re-use in the new cylinders (if the threads are the same) or, to defeat Toyota's "safety interlock" and grind down the sides of the wide foot until it fits.

I hope this helps anyone in the process of rebuilding wheel cylinders.
 
73fj40, as John Wayne said in, She Wore A Yellow Ribbon : 'good strong report...make Sgt in a couple years'.


All kidding aside...good information there.

Thanks, John
 
Ok. I know the front cylinders are a bigger bore than the rear but is it going to change anything or matter if I use them on the rear?


...via IH8MUD app
 
Last edited:
Why don't you try rebuilding the ones you have. Wheel cylinders are easy to rebuild, kits are cheap and they usually respond well to it.I have my originals for 37 years now and rebuilt them twice the last time this last summer-- work great no leaks and function perfectly after adjusting. I scratch arrows on the backing plates to help with the direction to turn to adjust.
 
QuackAxel said:
Ok. I know the front cylinders are a bigger bore than the rear but is it going to change anything or matter if I use them on the rear?
Click to expand...
Yes, it would matter quite a bit. Installing the more powerful front cylinders in the rear drums would make the rear brakes lock up way too early, tending to spin out the truck when braking & cornering on wet pavement. We call that an "Ah :censor: moment".
 
Good thinking. Get a hone for the internal cylinder, some more brake fluid to soak the cylinders in and some black spraypaint to make them look pretty.
Remember to anti-seize the inside and outside of the adjusters.
 
They really are not difficult to rebuild. There are a couple threads here on mud about it. Pighead is right get some good anti-sieze (I like permatex) and coat liberally where adjusters spin in cylinder. And don't panic if you see some corrosion or pitting this usually occurs behind the seal and not in the sealing area of the cylinder. Install, adjust and double check for leaks. Take your time its your brakes-- your A** is riding on them. If they are anything less than perfectly functional with no leaks when you are done discard and get new ones.
 
The generic parts stores will have a two stone hone that works fine. Auto Zone, NAPA, etc.
 
Well got my brake cylinders rebuilt. Just got the brakes bleed and now have a nice hard pedal! And no more leaks!! Can't take it for a drive since i have motor work going on but this is the first time the brakes have worked this good since I got this thing!


...via IH8MUD app
 
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