FJ40 Brake Bleeding troubles (1 Viewer)

[JAFO2014]

I have bleed brakes on just about every type vehicle. I've never had so much trouble as with my FJ40 this go round.
I replaced all the rear brake cylinders (2 each side). Also replaced the hard line that runs across the rear axle housing. Anyway, I have bled the brakes three different sessions, feeding three small bottles of fluid through the system and still the pedal sinks almost all the way down after the truck sits a few minutes. The system is really clean now and so I am recycling the fluid that comes out now. So it has been bleed, put that back in the reservoir, bleed.

I probably messed up in that I let the hard lines drip as I worked on both sides replacing the brake cylinders and getting the shoes back in place. So a lot of fluid came out of each line and am sure lots of air entered.

I started bleeding at the fartherist cylinder from the master cylinder. So I bled LR, RR, LF, RF. Kept going in that order several times, making sure to keep the master reservoir always full.

I am using DOT4, which I am sure you can use in place of DOT 3. Just not the other way around. DOT 4 has a higher boiling point.

I just ordered Russell 639560 speed bleeders (10mm x 1.0 thread) on Amazon. They will be in tomorrow. Am going to try those since the wife was getting bored doing the pedal pumping.

Any other tricks? I have heard people use some vacuum tool. Which one do people recommend?

Thanks for any feedback. Getting a bit frustrated.

 

[John McVicker]

It's a very frustrating job for sure. I think it's best to do it with 2 people. One underneath and one pumping on command. And I would change the order of bleeding to:
1) RR
2) LR
3)RF
4)LF
This order assuming you are a US vehicle with the master at the left front.

 

[Michael Hanson]

Hi, I agree two people make it easier but it still takes awhile. Don't let the master get too low . Mike

 

[Picz34]

What is the condition of your master cylinder? I had a hell of a time as well. Turn out the master cylinder was bad. Also when I was doing mine the cap to the master cylinder had a small vent hole in it. I was able to push air in there with the air compressor to bleed the brakes with air. It didn't work the best, but it did work.

 

[JohnnyC]

aftermarket cylinders? Or OEM?

Where did you buy them?

 

[45Kevin]

The shoes need to be properly adjusted.
There ain't a lot of room for error with the shoes, and if they are slightly too loose your pedal will go to the floor and you will need a second pump to get the shoes to grab the drum.

So my questions is, is it air still in the system, or not enough fluid in one pump to get the shoes tight against the drum?

 

[JAFO2014]

OEM cylinders. I can't remember where I got them. The receipt should be in the shipping box on the shelf. They have been on the shelf maybe a year. I was going to replace them sooner, but just got around to it. Nothing was failing, but I had them and figured I'd freshen things up before they leaked. I was swapping the rear differential back to 4.11 and thought I'd do the brakes as well.
I jacked up the rear at one point, removed the wheels and slid the drums off to make sure nothing is leaking. I don't see any leak anywhere. No leak at any line. All the brake hoses I replaced four years ago with the high quality hose with mesh outer sheath. The shoes are adjusted snug, so that you hear them scrape when the wheel is spun. I mean, I'm 59 and been doing my own brakes since I was 16. I have done an awful lot of brake work over the years. I have one of those check valve type bleeder hoses and was using that, as well as having the wife pumping the pedal. It has some brakes, but not enough. I actually drove the FJ to work yesterday. Have to pump once to get good brakes . I always leave a good following distance anyway, but I'm not driving it again until I figure this out. I don't want to cause an accident.
I do have a new master I could install. I have that sitting in my spares. But it worked just fine before I replaced the rear cylinders, so I figure it is air still in the system. I'll bleed some more and if no luck swap out the master.

 

[JAFO2014]

The shoes need to be properly adjusted.
There ain't a lot of room for error with the shoes, and if they are slightly too loose your pedal will go to the floor and you will need a second pump to get the shoes to grab the drum.

So my questions is, is it air still in the system, or not enough fluid in one pump to get the shoes tight against the drum?

Thanks. I will check again the shoe adjustment. I have them fairly tight, and I tried to make sure I had adjust the front and back cylinder on each side in unison, but i will triple check this.

 

[JAFO2014]

It's a very frustrating job for sure. I think it's best to do it with 2 people. One underneath and one pumping on command. And I would change the order of bleeding to:
1) RR
2) LR
3)RF
4)LF
This order assuming you are a US vehicle with the master at the left front.

I have always started with the far cylinder and then worked towards the master. On my 40 (yes, US version) the LR is the longest run of line. Then RR would be next. Then looks like LF is next with RF last.
But I'll try your order. Heck, I'd try it standing on my head facing east if that was the magic combination to get good pedal.

 

[Michael Hanson]

Hi, Any fluid leaking down the master cylinder or under the dash inside? You could always unbolt the master slightly and see if there is any fluid behind it. Mike

 

[JAFO2014]

Hi, Any fluid leaking down the master cylinder or under the dash inside? You could always unbolt the master slightly and see if there is any fluid behind it. Mike

Thanks. I looked yesterday inside, but I have not removed the master to examine beyond looking from inside the cabin. I'll do a few more rounds of bleeding once the speed bleeders arrive and it no luck will swap the master. I did some searching on this site and see where one member made some hard lines to "bench bleed" the master in the truck. Just lines he screwed in the two ports that curved back into the reservoirs so he could pump the pedal and bleed the master. Might try that as well if I swap the master. Heck, might try that even if I don't swap the master. There is air in the system someplace and it obviously likes its new home.

 

[JohnnyC]

Do you have the tire mounted when adjusting the shoes ... the tears are a pita ... I too have done many adjusting to lots of different vehicles and was at a time ASE very in brakes and the rear TLC drums are a pita

Most likely if you did use oem cylinders then the issue is adjustment

If the were aftermarket air gets trapped at the top of the cylinder

If you are not getting air out ... it’s adjustment


Adjust to you can’t move them and then back off 3 clicks

 

[John McVicker]

What JohnnyC said. Back off only 3 clicks. The manual says 5 clicks, but that is way too much.

Adjust them tighter than you would think you should. Bleed them and then go for a test drive. Before you start pumping the brakes...COAST to a stop. Get out and feel your wheels, at this point warm is ok. Warm, not hot.

EDIT:
At this point in your adjustment process, if the wheels are cool they are not adjusted tight enough, they need to be warm. Once your drums are tight...or too tight, you can then back them off one click at a time and then go for a test drive until you get the feel you want.

Personally, I'd rather have them too tight at first rather than even one click too loose.

 

[JAFO2014]

Do you have the tire mounted when adjusting the shoes ... the tears are a pita ... I too have done many adjusting to lots of different vehicles and was at a time ASE very in brakes and the rear TLC drums are a pita

Most likely if you did use oem cylinders then the issue is adjustment

If the were aftermarket air gets trapped at the top of the cylinder

If you are not getting air out ... it’s adjustment


Adjust to you can’t move them and then back off 3 clicks

I'll try that, thanks.

 

[middlecalf]

I read through all this a couple of times, but maybe I missed it. In any case, you need to start by bleeding the master cylinder first.

 

[JAFO2014]

I read through all this a couple of times, but maybe I missed it. In any case, you need to start by bleeding the master cylinder first.

I guess I have not actually totally bled the master. I bled the line that goes to the rear. I'll see about bleeding both. I've never in the past had to bleed the master when I was replacing the calipers and wheel cylinders. But, that was different vehicles, not a 40. Maybe this is a totally different animal when it comes to brake bleeding. I know I should be an expert by the time this is over. Or maybe it will be on the side of the road with a FREE sign on it. Well, I don't think I'll get that frustrated.

With the lines exiting the top of the master I figured any air would be exiting the master fairly easy.

 

[Pete]

I've never bled the M/C except for bench bleeding (actually "vise" bleeding) a new one. I'll bet dollars to donuts that adjustment is your problem unless there is a leak someplace in your system. Just to be sure I'd check every fitting in your system.The first time I ever bled FJ40 brakes I went through almost word for word what you have described including wearing out the leg of my honey who was not my wife . This was in the days before the internet when on-line tech forums didn't even exist. A buddy more experienced with FJ40s than I was at the time clued me in on the adjustment. Pinhead on here has one of the best explanations of how to properly adjust. As others have said too tight is better than too loose. I have those speed bleeders you referred to on my old 944 and they work great. On my FJ40 I use my MityVac.

Good luck!
Pete

 

[pondjumpr]

Interesting topic. I am going through the exact same issue on my 78. I replaced my front disc -rotors, pads, etc. about 2 years ago. Brakes have been fine. I cleaned up my truck and noticed a slight leak on one of my driver's side rear brake cylinders. I ordered two new cylinders for the driver's side rear. Replaced them and tried to bleed the system. I get full squirt up front but only drip in the rear. Lots of clean fluid, just not a heavy squirt when trying to bleed. This weekend, I replaced the other two wheel cylinders, passenger side. The brakes will not even stop the wheel in a free spin while up on jack stands. I have tried and tried to bleed but I can't get a good pedal or make the rears work. The front brakes are still Ok, just not as good as they were. I did RR, LR, RF, LF in that order.

After reading several threads on MUD, I am going to try to adjust the shoes tighter than I thought I needed to. I didn't replace lines on mine but fluid is clean and I haven't run the reservoir dry. Try, try again, I guess...

 

[Pete]

The left rear (driver's side) wheel is the farthest from the M/C measured along the brake line and should be bled first followed by the right (passenger) rear. I think the RF is next and then the LF but I'd have to look to be sure about the fronts.

Pete

 

[Pin_Head]

Did you install the wheel cylinders upside down with the bleeder at the bottom? They are really hard to bleed this way.

You don't mention wheel adjustment, but this is really important, as others have pointed out. How did you adjust them?

Tighten up each adjuster until the wheel can't move and then back off 2 clicks. (I prefer two with new shoes; you can go 3 with old shoes).

Things that don't matter: bench bleeding the master. The order in which you bleed the cylinders.