Leaking Brake Fluid

RBBailey

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
There is a puddle.

It is coming from where the master bolts to the booster; running down, and dripping on the floor from the bottom of the booster.

  • Typical? Replace? Rebuild?
  • Am I going to need to clean out the booster, or get a new one as well?
  • And when replacing, other than the two mounting bolts, how does it attach to the booster mechanism?
 
Napalm00

Napalm00

Technical Excellence Contributor
Replace, typical... The lr masters suck
No cleaning required lr booster is sealed in front except for the pushrod hole, just wipe it clean
Two nuts and the brake lines


Notes:
Use flare wrenches on the brake lines
You will have to bench bleed the new master (see youtube)
You can replace everything with gm parts if you want a nice upgrade and cheaper parts.. See here https://nas-row.com/showthread.php?t=1346
 
1of40

1of40

Well-known member
Napalm00 said:
Replace, typical... The lr masters suck
No cleaning required lr booster is sealed in front except for the pushrod hole, just wipe it clean
Two nuts and the brake lines


Notes:
Use flare wrenches on the brake lines
You will have to bench bleed the new master (see youtube)
You can replace everything with gm parts if you want a nice upgrade and cheaper parts.. See here https://nas-row.com/showthread.php?t=1346
Click to expand...


Are LR masters really that bad or is it lack of basic maintenance? I've got a 34 yo truck on the original master and a 20 yo truck on the original master. I just simply replace fluid when it get dark and always use fresh DOT4.
 
Napalm00

Napalm00

Technical Excellence Contributor
They just suck. They make the fluid dark quickly due to the garbage seals, the braking power they generate is low compared to the same size gm unit when new and they are expensive compared to the gm units. It's also nice after the conversion if you have an issue to be able to go to any parts store and get a master for about $25

You can actually use the corvette style universal master on the lr booster, it fits just fine if you widen the mounting ear holes just a tad.

Of course your experience may vary, I went through three early 110 Masters then did the conversion. (original, replacement trw, replacement genuine) others may naively tell you with blinders on they they have never seen a problem, guess they need to open thier eyes.

Of the few people who have done this conversion since I posted it, they have all loved it!
 
1of40

1of40

Well-known member
Cool. Better braking would be welcome, so if mine do go i'll strongly consider it.
 
R

Red90

Well-known member
IME, most people just have their braking system in bad shape. The stock system should let you lock up all four tires with only moderate pressure on the pedal.
 
RBBailey

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
I can lock them up.... but that might be because of my tires, not my brakes....
 
Napalm00

Napalm00

Technical Excellence Contributor
Then the leak is from the rear seal, secondary circuit is probably doing most of the work if you have pwda or similar still installed
 
Napalm00

Napalm00

Technical Excellence Contributor
The master has three seals. One near the booster, one in thr middle of the master rod and one near the end.

Yours near the booster failed,it would be near the words "to pedal" in this generic diagram.

master-brake3.jpg


Pwda is a saftey valve/sensor/circuit joiner. Some trucks have them, some have g valves some have a combo of the two. Located on the firewall or frame rail, depending on build
 
RBBailey

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
I'm pretty sure I don't have the PWDA. EDIT: I know what you mean now, but I can't remember... I'm pretty sure it does not have any kind of circuit running to it.

I'd guess that my primary piston seal is leaking, since that is where the fluid is coming from.

Thanks, I'm buying a new cylinder tomorrow. I'll go through the process of a full system bleed to all new fluid.
 
RBBailey

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
By the way, when bench bleeding, have you found better luck using hoses back into the reservoir, or by blocking the ports and pumping?
 
RBBailey

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
Yeah, I had seen that thing in the brake lines before, didn't know exactly what it did, other than I figured it was a distribution valve. Never heard of a PWDA before. No light on the dash.

What's interesting about this whole thing is that although it really started leaking lately, after the big drive two weeks ago; I didn't noticed any difference in the braking, except for the slight feeling that it is probably time to adjust the rear drums. But I think it's been leaking longer than that.

The three other people who have Rovers who have driven my truck all commented, almost within the first minute or two, about how nice my brakes feel!

I'll give it a quick drive up my street tomorrow to see if I can notice anything different, just so I know what to feel for the next time there is a fault like this.
 
Napalm00

Napalm00

Technical Excellence Contributor
Np dude, if it's there and you are replacing the master it's def worth rebuilding the Pwda. Probably full of 30 years of gunk
 
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