72 fj55. all 4 wheels are drums still. I have been getting the typical double pump on the brake before i get solid brakes. adjusted all wheel cylinders and bleed both front and back. still squishy. i did notice moisture (brake fluid i assume) on top of the front cap reservoir of the mc. is that normal? also noticed that when i was pumping and bleeding that a big air bubble would appear in the front reservoir. Surely that cant be right....since the back wasnt doing it? So my question is....is it a bad mc? still air in the line? or do i need to keep adjusting wheel cylinders. and yes i know the wheel adjustment method. any help or opinions would be greatly appreciated.
brake problems
- Thread starter Jake77fj55
- Start date
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Hey Jake,
Did you replace the MC when you went through and bled the system? If so, did you bench bleed the MC before installing? If you are seeing an air bubble in the reservoir, you absolutely still have air in the system, which is most likely the cause of your squishy brakes. If it's a new MC and it wasn't bench bled, chances are you have air in the cylinder itself still.
Did you replace the MC when you went through and bled the system? If so, did you bench bleed the MC before installing? If you are seeing an air bubble in the reservoir, you absolutely still have air in the system, which is most likely the cause of your squishy brakes. If it's a new MC and it wasn't bench bled, chances are you have air in the cylinder itself still.
- Thread starter
- #3
No it is not a new MC. I shouldnt have fluid on top of my reservoir cap though right? Or is it just venting out a bit when the bubble happens? I will bleed the crap out of them again tonight. And ive noticed that when i adjust out my wheel cylinders until i can here the brake shoes rub a bit then stomp on the brakes it doesnt seem to make the rubbing sound when i spin the wheel again.
Well, if there are bubbles - there is air in your lines. I've never seen brake fluid on top of my cap - the cab is there to prevent that! So it sounds to me like you're probably blowing air bubbles out the MC. That or you have a vacuum issue that's somehow blowing your fluid out. My truck had some sort of vacuum malfunction once that blew the front reservoir's cap clean off. Still not sure how it happened. That said, this is most likely not your problem.
Sounds to me like the shoes aren't resetting all the way, which, again, could be due to air in the lines, causing the "double pump" to make full contact issue. The other thing you can always check is the distance between the booster rod and the MC rod - but again, if you didn't disconnect the MC or adjust the pedal or rod lengths at all, this is most likely not the problem.
Very long story short - this sounds like air in the lines. More specifically, a stubborn bubble on the MC or upper lines near the MC. Bleed away! Maybe have a friend hit the brakes of you haven't already so you can really see what the heck is happening with the cap - that seems odd to me.
Sounds to me like the shoes aren't resetting all the way, which, again, could be due to air in the lines, causing the "double pump" to make full contact issue. The other thing you can always check is the distance between the booster rod and the MC rod - but again, if you didn't disconnect the MC or adjust the pedal or rod lengths at all, this is most likely not the problem.
Very long story short - this sounds like air in the lines. More specifically, a stubborn bubble on the MC or upper lines near the MC. Bleed away! Maybe have a friend hit the brakes of you haven't already so you can really see what the heck is happening with the cap - that seems odd to me.
- Thread starter
- #5
Thanks,
I will keep bleeding away. On a lighter note i ran into a serious land cruiser hoarder. All of them are just rusting away except for the truck in garage. tried to buy a couple but i think he just wants to say he owns them....what a shame.
I will keep bleeding away. On a lighter note i ran into a serious land cruiser hoarder. All of them are just rusting away except for the truck in garage. tried to buy a couple but i think he just wants to say he owns them....what a shame.
Other thing to check is all your hose connections. Make sure none are loose. Obviously they'd probably be leaking if that was the case but its just another place your system could be sucking in air.
How tight are you adjusting the wheel cylinders? You should tighten them until you can't turn the tire, then back off 2-3 clicks. When adjusted right, you should just barely be able to spin the tire one turn with a good effort.
Did you change anything that would get air in the lines?
- Thread starter
- #8
sounds like i am not adjusting the wheel cylinders enough. i was under the impression you are suppose to stop when you can hear/feel a slight drag on the shoes. And yes i have replaced some of the wheel cylinders about a year back. but that fixed the problem that time. It would stop on a dime. well tonight when i get home i am going to adjust more and bleed more. Actually first i am going to pull the drum off and do some investigating. Thanks for your help. I will post my results.
- Thread starter
- #9
oh and another thing. It seems like im adjusting them out quite a few clicks before i even get anything (shoes rubbing). On my front driverside i think it was like 30 turns per cylinder. Not full revolutions but you know what i mean. backs didnt take nearly as much as the fronts. but i need to adjust them out more anyway sounds like.
There's not enough "throw" in these cylinders to allow you to run with almost no drag. It was surprising to me how much drag is required to get these brakes to work properly. You'll need to hit the brakes every now and then during the adjustment to get the shoes to seat and then hopefully pull away centered. If you're pulling the drums (which is a good idea), I'd clean up the dust, put some brake lube on the spots where the shoes ride on the backing plate, and double check the direction you need to turn each adjuster.
I thought i was going crazy when I couldn't get mine adjusted but when I took them apart, I saw that the PO had used the wrong cylinder in a couple of locations, so the adjuster turned the wrong direction. Good luck.
I thought i was going crazy when I couldn't get mine adjusted but when I took them apart, I saw that the PO had used the wrong cylinder in a couple of locations, so the adjuster turned the wrong direction. Good luck.
- Thread starter
- #11
well somehow my one of my wheel cylinders pulled away when i was trying to apply brakes to center shoes and adjusting. Gonna put it back together and inspect the rest of the drums and start ALL OVER AGAIN tonight. Thanks for all the advice.
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- #12
I was informed on mud that a rule of thumb for adjusting wheel cylinders was that the adjuster wheel or tool always turned towards the axle in order to tighten. Not the case in mine. Some sets do. Some sets do the opposite, and on another the set goes opposite of each other?! Finally got the correct pattern for which way each one adjusts. Adjusted them all out until the wheel was difficult to turn. Backed off 3 clicks. Oh and bleed the lines again. Still squishy pumping brakes until the third or fourth pump....master cylinder bad? I have not tried bleeding the mc yet. Wasnt sure if that waould be the problem or not. Any suggestions?
I'm facing the exact same problem. Gallons of DOT3 with the shoes locked against the drums, and it's still double pumping. Since I could hold a firm pedal on the second pump, I thought I could rule out the MC, but at this point I'm ready to start throwing parts at it. New MC arrives Friday.
- Thread starter
- #14
Im just confused on these damn wheel cylinders. I originally struggled with my 77's rear drums but replaced all wheel cylinders and mc. worked fine after that but of course it had disc up front. The 72 fj55 im not sure whats going on with these.
Ahh... I miss my drum brakes... 
Have you tried a vacuum bleeder?
I've not adjusted my front brakes in 20 years... 15 years for the rears. Got 4wheel discs now. I'm sure they're cheaper in the long run. And they'll stop on a dime, even after a river crossing
Have you tried a vacuum bleeder?
I've not adjusted my front brakes in 20 years... 15 years for the rears. Got 4wheel discs now. I'm sure they're cheaper in the long run. And they'll stop on a dime, even after a river crossing
- Thread starter
- #16
and to correct myself. wheel cylinders turn the way they are suppose to. when i was writing my findings i think i was upside down on keystones. And for an update i have bleed them a ridiculousl amount of times but now 2 pumps firm instead of three. and i need to loosen my passenger front adjustment i gues because my wheel is pretty damn hot after going around the block about 3 times.....
- Thread starter
- #17
I would like to convert to the disc in front. Almost did a month ago but my 78 fj55 (parts) purchase fell through.
