Builds A New 55 Owner Intro (cgn1976 thread) (4 Viewers)

[scrapdaddy]

That's your axle breather, nothing to do with the brake lines.

 

[Cgn1976]

Hah. Well I can rule that out. Thanks!

 

[scrapdaddy]

What is the fluid around the vent, gear oil or brake fluid?

 

[Cgn1976]

Not really sure. Gotta clean it off better to try to figure it. I just re-bleed the system. A few bubbles came out. I've noticed they last few times I get in the truck after it sits, the pedal goes to the floor the first press, then part way on the second before firming up. What's that about?

 

[RUSH55]

Sounds like the master cylinder possibly isn’t relieving. Don’t remember if you replaced the master or not...

 

[scrapdaddy]

the pedal goes to the floor the first press, then part way on the second before firming up. What's that about?

That sounds like your master cylinder. Did you bench bleed it first?

 

[Cgn1976]

Thx guys. It is a new master and I did bench bleed it

 

[RUSH55]

Do you have a booster or are they manual?

*Just found where you mentioned replacing the booster without disconnecting the master.*

Something hay-wire here

 

[Cgn1976]

Do you have a booster or are they manual?

*Just found where you mentioned replacing the booster without disconnecting the master.*

Something hay-wire here

I do have a booster. That was what started me down this road in the first place. It was leaking air. Replaced it and as I was putting it on, I realized my master was shot so got a new one of those. Bench bled it, installed it and started getting the wierd soft then hard pedal stuff. Found a bad cylinder. Replaced them all. Testing it, blew a soft hose. Replaced them all. Now adjusting and tweaking the cylinders. Thought I was good this morning. Long drive, pedal got steadily harder. Came home, let it cool, got in, pedal to the floor first 2 pumps, then felt good. I re bleed. Feels good but still seems like something is wrong.

I just read another 40 thread that sounded very similar to this. New master with no relief valve. Mine is an Aisin so I assume it has one, but not even sure what or where it is. Do I bench bleed it again then rebleed the whole thing again?

 

[bobm]

AIR in the system! BLEED again

 

[Cgn1976]

AIR in the system! BLEED again

I got a bench bleed kit so I think can do it while installed.

 

[bobm]

I may have spoken too soon. Took a nice cruise and the pedal got steadily stiffer and had less play until it was hard all the way at the top. I could tell there was a little increased rub on the shoes so I opened up the cylinders a little and that helped some. I'm guessing I'm still in the adjustment phase however I noticed this on the back T fitting. I don't see anything about it in the Haynes Manual or the FSM pdf I have...so what is this and why is it leaking? Feels like a pressure relief valve or something. I'm guessing this isn't a good thing. Also seems like the fluid leak would cause a softer pedal...not sure why it would get harder as it drove. Again I have a brand new booster, brand new master, brand new soft lines and no leaks on the hard lines. I was gonna go back and bleed again to see if there's any air in the lines again. Any thgouts are helpful.

The pic below is a little bit of an optical illusion. There is no line coming out of the top of that leaking valve/fitting. Just the hanger for the sway bar View attachment 2649099

I believe that's a proportioning valve for your brakes, not a breather for axle! It has brake lines feeding in from both sides. That's where your air leak is

 

[RUSH55]

Yeah, if you bench bleed it again, you’re going to have to bleed everything again. Now I’m wondering if you have the right master. The pedal getting steadily harder sounds like a stuck relief. The pedal to the floor and requiring pumping sounds like air in the system or fluid loss. You need to verify that you are for certain not losing fluid anywhere, and you for certain have the correct master for an all drum system. There should be no proportioning valve on the all drum system.

 

[RUSH55]

I believe that's a proportioning valve for your brakes, not a breather for axle! It has brake lines feeding in from both sides. That's where your air leak is

It’s the breather and brake line “T”. Should not have a proportioning valve in the system unless there is only one hard line coming out of the master which in case would go to a splitter to separate the front from rear.

So the 1976 disc brake front should have a dual reservoir master. IIRC, the larger res feeds the front. From the master they cross along the firewall to the passenger side and the front most drops down to feed the front calipers and the rearmost drops to the side of the frame rail and runs to the rear axle.

Anywho, keep digging. This issue has got to be something obvious!

 

[scrapdaddy]

New master with no relief valve.

That's a Residual valve I believe you're talking about. It's needed for drum brakes, but with the pedal going to the floor like that I'm guessing air is getting in the system somewhere or the master has trapped air in it.

 

[Cgn1976]

Well I re bench bled it while installed. Bubbles came out for sure. Re bleed all four corners. No leaks I can see anywhere. I looked up axel breathers and they do match whats in the pic, although it's clearly running through that T fitting for the 2 rear hard lines. I don't know if that's normal or not. I'm 99% sure the master is right. It's for the right year, for all drums and looked like what came off, which was original. I see a tiny relief hole on the front of it..it has a copper bolt on the passenger side that lets fluid out if you open it.

When I first pumped the pedal after doing everything just now, to the floor twice, then solid. Gonna go back ina bit and see what it does. If it's soft again, Im gonna break something. Lol

 

[scrapdaddy]

I looked up axel breathers and they do match whats in the pic, although it's clearly running through that T fitting for the 2 rear hard lines. I don't know if that's normal or not.

That's normal, don't ask me why Toyota did it like that, but normal. I bought a new Aisin clutch master that would never bleed out right? I never could figure it out, so bought another and no more problems. Was it me or the master, don't know. All I know is that's just my luck, redo two or three times to get it right.

I wish I knew more to help, all I got.

 

[Cgn1976]

Soft pedal, to the floor after an hour of sitting. 2 pumps, then solid. Seems like there's no difference after another bench bleed and re-bleed. Can I seriously be that guy who got a bad brand new Aisin master?

 

[Cgn1976]

Test drove it after the soft pedal 2 pump move and the brakes are absolutely the best they've ever been. I can tell it does feel like the pressure is building the longer I drive it. Reminds me of this thread. Mine totally locked up like that last weekend but that was before the new soft lines. So damn close but something just isn't right.

71 fj40 front brakes locking up

I have a 1971 FJ40 Drum brakes all new cylinders, shoes and drums. It also has new brake booster and master cylinder. It was fine for the first 20 miles then I drove it to get inspected it passed but they said my brake pedal was really hard with vey little play. When I got in the car to...

forum.ih8mud.com

 

[PabloCruise]

Did you ever check/adjust the clearance of the push rod?