FJ 62 brake pedal goes to the floor (1 Viewer)

[Gimme a 60]

Help! In my FJ 62 the brake pedal presses all the way to the floor, though the pedal travels a great distance, it doesn’t seem to affect its ability to stop. However it’s still concerning and I don’t trust it, I can not figure out why it’s doing this. SO what I did was bleed the brakes very thoroughly, replaced the master cylinder, and the same problem still occurs. Is there possibly something wrong with the drum brakes? The previous owner replaced the front pads as well.

Thanks!

 

[aljollano]

Does it feel spongy? Sounds like your booster is not working.

A.J

 

[Lead Head]

A bad booster either causes a very hard brake pedal, or an over-boosted pedal (as in, you barely touch the pedal and it flies to the floor sending you through the windshield). It will not cause a long-travel, however.

Did you bleed the brake portioning valve? It's a common point for air to be trapped. There are lot of rubber lines on an FJ-62, and if any of them are failing, it could cause a soft pedal with excessive travel. I have found on my FJ62 that rear brake adjustment is critical to pedal feel, as well. If the shoes are too far from the drum, you will have almost zero pedal feel until the shoes finally hit or the master's rear piston strokes out and starts actuating the front piston.

 

[too tall]

Is this a new problem that just started ? Are the rear shoes in proper adjustment? does the e-brake work ?

 

[Gimme a 60]

Is this a new problem that just started ? Are the rear shoes in proper adjustment? does the e-brake work ?

I bought it with the brakes like that, he also said to not pull the E-break because it will stick on.

 

[Gimme a 60]

Does it feel spongy? Sounds like your booster is not working.

A.J

It’s not spongy, it feels like a completely normal brake when it starts to contact.

 

[Gimme a 60]

A bad booster either causes a very hard brake pedal, or an over-boosted pedal (as in, you barely touch the pedal and it flies to the floor sending you through the windshield). It will not cause a long-travel, however.

Did you bleed the brake portioning valve? It's a common point for air to be trapped. There are lot of rubber lines on an FJ-62, and if any of them are failing, it could cause a soft pedal with excessive travel. I have found on my FJ62 that rear brake adjustment is critical to pedal feel, as well. If the shoes are too far from the drum, you will have almost zero pedal feel until the shoes finally hit or the master's rear piston strokes out and starts actuating the front piston.

I don’t even know what a portioning valve is, will have to look into it, it doesn’t leak any fluid anywhere. I feel like my best bet is the rear break shoes not being in adjust. Thanks

 

[Seth S]

Based on what you’ve said I’d suggest jacking up the back and pulling the drums. Inspect the brake linings, mechanism, and wheel cylinders. You might have no pad material left or the wrong wheel cylinders

 

[Seth S]

I don’t even know what a portioning valve is, will have to look into it, it doesn’t leak any fluid anywhere. I feel like my best bet is the rear break shoes not being in adjust. Thanks

Proportioning valve. It’s a little valve that varies brake fluid flow based on how much suspension sag there is in the rear. Basically the more weight you are carrying the more rear brakes you need and more fluid goes to the drums. When you have the rear wheels off the ground the valve is at its minimum flow.

 

[franklin40]

rear brakes need to be adjusted. while in there pull the ebrake bell cranks sort and clean them up. they have aluminum guides if i recall and corrode easily and then stick. get them cleaned up and working. it’s not hard. then adjust the rear brake shoes. then bleed the lines from furthest to closest including the load sensing proportioning valve. it’s up infront of the rear axle. it’s designed to change the amount of force the rear brakes supply. when the back of the truck is loaded down the springs compress and the distance between the body and axle changed. this adjusts the lspv.

here’s a picture of what it looks like but this person put a spacer in because the truck was lifted. (does your have a lift ?)

there will be a bleed screw on it you can use to bleed it after you do the rear axle

 

[Gimme a 60]

rear brakes need to be adjusted. while in there pull the ebrake bell cranks sort and clean them up. they have aluminum guides if i recall and corrode easily and then stick. get them cleaned up and working. it’s not hard. then adjust the rear brake shoes. then bleed the lines from furthest to closest including the load sensing proportioning valve. it’s up infront of the rear axle. it’s designed to change the amount of force the rear brakes supply. when the back of the truck is loaded down the springs compress and the distance between the body and axle changed. this adjusts the lspv.

here’s a picture of what it looks like but this person put a spacer in because the truck was lifted. (does your have a lift ?)

View attachment 2871665

there will be a bleed screw on it you can use to bleed it after you do the rear axle

Yes it has a 2” OME lift. I will have to look into this unique valve, that’s the one think that I haven’t looked at, but to be fair I don’t have much mechanical experience, and have NEVER done brakes.

 

[OSS]

Nows as good a time as any to learn!
None of us had done brakes at one time. Only way to learn is dive in.

 

[Godwin]

When replacing a master cylinder it's important to check and, if needed, reset the push rod length on the brake booster. This cheap tool Power Brake Booster Tool - https://www.macsautoparts.com/power-brake-booster-tool-42-397920-1.html?utm_source=bing&utm_medium=cpc&cmpid=339371181&agid=1240249206685998&tgtid=pla-4581115206957043&prdid=42-397920-1&scid=scbplp42-397920-1&sc_intid=42-397920-1&gclsrc=aw.ds&&utm_campaign=sc_bingshopping_remnant&msclkid=846eaab8816a17fb12c8cb7bee8e8161 makes it easy. If the booster rod is too short you'll not have fully actuation of the master cylinder piston.

 

[Gimme a 60]

When replacing a master cylinder it's important to check and, if needed, reset the push rod length on the brake booster. This cheap tool Power Brake Booster Tool - https://www.macsautoparts.com/power-brake-booster-tool-42-397920-1.html?utm_source=bing&utm_medium=cpc&cmpid=339371181&agid=1240249206685998&tgtid=pla-4581115206957043&prdid=42-397920-1&scid=scbplp42-397920-1&sc_intid=42-397920-1&gclsrc=aw.ds&&utm_campaign=sc_bingshopping_remnant&msclkid=846eaab8816a17fb12c8cb7bee8e8161 makes it easy. If the booster rod is too short you'll not have fully actuation of the master cylinder piston.

Thanks!

 

[Lead Head]

I don’t even know what a portioning valve is, will have to look into it, it doesn’t leak any fluid anywhere. I feel like my best bet is the rear break shoes not being in adjust. Thanks

If you look at your rear axle, you see a weird little metal rod on a hinge type deal. The metal rod will run up towards middle of the land cruiser to a little dingus bolted to the frame. If you look at this dingus, you will see 3 brake lines and a bleeder valve. This is your rear brake proportioning valve, it needs to be bled. Here is my usual bleeding order when doing brakes on my FJ62:

Proportioning Valve
Rear Left
Rear Right
Proportioning Valve (again)
Front Left
Front Right

 

[Gimme a 60]

If you look at your rear axle, you see a weird little metal rod on a hinge type deal. The metal rod will run up towards middle of the land cruiser to a little dingus bolted to the frame. If you look at this dingus, you will see 3 brake lines and a bleeder valve. This is your rear brake proportioning valve, it needs to be bled. Here is my usual bleeding order when doing brakes on my FJ62:

Proportioning Valve
Rear Left
Rear Right
Proportioning Valve (again)
Front Left
Front Right