how to remove residual valve for disk brakes or . . .

[fyresq]

That valve that you have pictured is the exact one that I pulled out of my 71. Gonna do another one on a buddy's 55 tonight who swapped to mini outers and discs. He has to pump the brakes even after bleeding them and I'm betting he still has the residual and not getting enough fluid.

 

[Poser]

From this page: https://forum.ih8mud.com/40-55-series...nder-mods.html

There is a very good discussion about the type of valve I have (as you had). Some say that I should leave this valve becasue it is 2#s and can be run for both disk and drum and others say it should be removed. Oh the fun of modifications.

Junk link by the way...



Sure you can leave it in there, and then come out here and start another "my front brakes are dragging and I don't know why" thread.

psst- there is information on this in the FAQ section


Simply driving your truck up and down the street is not definitive proof that your front brakes are not dragging.


Did you feel the rotors?
Did you jack the front of the truck up off the ground and try and rotate a tire?




Oh and that thread you were trying to link/reference is not proof positive of anything other than lostmarbles is a proper screen name for the thread author.




By the way, do you own a digital camera?

 

[slickrock]

Removing it when I get home. . . And lovely picture of the valve for Poser will follow.

 

[bsmith123]

Brake Valves

Here's a few thoughts on the valve with the hole, just a theory

Maybe it works like a residual valve but does not keep the pressure on the line (small amount of head pressure from the MC) In effect, no residual valve

Instead as line pressure drops fluid is metered through the smaller hole slowing it so it drops off without creating a negative pressure in the line ----pulling air in at the calipers. Not a concern with a residual valve because you always have pos pressure.


To work as well as designed it seems a Disc/Drum combo would likely have a metering valve and a proportional valve

The proportional valve sends less pressure to the front than the rear and the metering valve makes sure the rear brakes get pressure before the front brakes. These may go together as a combination valve.


Other things can come into play such as bore size in the MC---the bigger the bore the less stroke is required to displace the same amount of fluid.


So it seems there can be a variety of results when mixing and matching parts from different years, systems, and vehicles


Even if it seems okay seat of the pants---is it performing as well as designed? How close is okay and what are you basing that on?

In the UK they do a rolling road force check on your brakes during the annual inspection and if you meet the standard you are okay--in a way it would be nice to have that back up here

 

[lostmarbles]

Ah. It gives me great pleasure to see this debate continuing. (I had been ignoring this thread but eventually decided to take a squizz because its length suggested it may have got interesting.)

I never did get to the bottom of what those "thingies" actually do in my master cylinder.

In fact, that very same "thingie" pictured above (my photo) is still happily doing whatever the hell it is meant to do inside my BJ40's master cylinder outlets right now as we speak. (Err - well perhaps it may need me to be driving, or braking, or panic-stopping with air-contamination, or .......who knows? ... for it to do its as-yet-unconfirmed job.)

It certainly is NOT a "residual valve" because it CAN'T (with any stretch of the imagination) leave "residual pressure".

As far as I know their existence could still be "safety related" - I abandonned that thread (now linked to this one) only because I became less certain of this.

But I am certain that leaving those "thingies" (as pictured in post #24) in place can't cause "brake drag" by leaving "residual pressure" in wheel cylinders (either discs or drums).

 

[Poser]

But I am certain that leaving those "thingies" (as pictured in post #24) in place can't cause "brake drag" by leaving "residual pressure" in wheel cylinders (either discs or drums).

How have you proven this?



I do know for a fact that when I left them in a drum brake master cylinder circuit that was being used with disc brakes that the disc brakes would drag.


But what do I know.

 

[slickrock]

After I removed the valve, bled the lines ,and did father stuff after work yesterday, it was dark outside and I didn't want to risk driving and getting stuck at night. Nothing like a pissed off wife that had to get her sleeping child out of bed to go help daddy with his stuck cruiser becasue of his brakes.

Wlil take it for a drive right after work and upload the picture of what I removed. It is the same thing that is in post 24

 

[Pighead]

It is the same thing that is in post 24

Funny, looks just like what i pulled out of my MC to make the front discs work....

 

[lostmarbles]

How have you proven this?....

The assembly in the picture (taken by me) in post #24 by bsmith123 shows the item we are talking about it.

And here is another view of it:



When inside a "mastercylinder outlet", the "not insignificant hole" in the top of that "cup" (which is the item on the furtherest left above) ensures there is ALWAYS a permanent flow path that will ALWAYS act to equalise pressures.

So the onus is on YOU to prove what you say Steve. (The photos are "complete back-up" that proves what I'm saying.)

....I do know for a fact that when I left them in a drum brake master cylinder circuit that was being used with disc brakes that the disc brakes would drag....

Perhaps the one you removed was in fact this type (which I have never had the opportunity to examine):

But what do I know. ...

He he he. And ......... but what do I know too????

 

[Pighead]

[/U][/I]

But what do I know.

He he he. And ......... but what do I know too???? [/QUOTE]


Somebody had to say it....

 

[lostmarbles]

Funny, looks just like what i pulled out of my MC to make the front discs work....

Ah. I love posts like this!

So we can assume they dragged before you "did the deed"? (That's what you're implying!)

Or did you just blindly obey what everyone does (in discarding your front "residual valve") and found you ended up with "no brake drag" and therefore perhaps you concluded that this justified the removal?

At least I believe Slickrock has identified for himself that these things (pictured in post 24) can't leave residual pressure (no matter what you folks say to the contrary).

 

[Pighead]

Yup, just blindly pulled it and threw it far into the bushes....no problem as yet, it's been 4 years.

 

[srgould41]

Hehehe... I know you don't know what I know, but I don't know what I know either so there!


There is no way in hell I am going to crack my brake lines after spending more than a week getting them bled, otherwise I would volunteer.

How about someone in the middle of this get a pressure gage hooked in-line and solve the mystery, once and for all, with tested facts???

He he he. And ......... but what do I know too????

Somebody had to say it....[/quote]

 

[lostmarbles]

Hehehe... I know you don't know what I know, but I don't know what I know either so there!


......solve the mystery, once and for all...

[/quote]


Of all the topics that have appeared on MUD since I discovered the site (couple of years ago now), this is the one that I would most like to be solved ONCE AND FOR ALL. (Despite all the fun of taking part in these discussions.)

Here's a view inside the "cup" showing the hole responsible for ALWAYS equalising the pressures (and thus for PREVENTING THE ASSEMBLY FROM LEAVING RESIDUAL PRESSURE):



.............just saying. (I know this evidence still won't be satisfactory for some. )

And I used to know most of what I know but lately less of it makes sense. But plenty of people out there apparently consider
this case closed. ("They're F'in residual valves and that's all there is to to it. Ya remove the front one when ya replace da front drums with discs".) Now........Do these people (with this viewpoint) really know what they know? Or do they just THINK they do? And is "knowing" really important here? Is there light at the end of the tunnel? Why are we here? Do we exist or are we imaginary?...........................................................Is this all part of some plot..................................................Errr. Brain malfunction. Brain malfunction........................Going back outside to work on my cruiser now for some therapeutic repetitive paint-scr@ping activity. (Repetitive activity like chanting "Hari Krisha", banging your head against the wall, or scr#ping paint are known to sooth troubled-minds ya know.)

 

[Poser]

So the onus is on YOU to prove what you say Steve.

With the pieces in your picture installed in a drum brake master cylinder being used to actuate disc brake calipers, the front disc brakes would drag.


After that piece was removed, the brakes did not drag.

How much more simple does it get bud?

In fact, that very same "thingie" pictured above (my photo) is still happily doing whatever the hell it is meant to do inside my BJ40's master cylinder outlets right now as we speak.

Which, again, according to your signature, is a drum brake truck. How is this information in your post applicable to a master cylinder in a disc brake equipped vehicle again?

Have you converted your truck over to disc?

And I used to know most of what I know but lately less of it makes sense. But plenty of people out there apparently consider
this case closed. ("They're F'in residual valves and that's all there is to to it. Ya remove the front one when ya replace da front drums with discs".) Now........Do these people (with this viewpoint) really know what they know? Or do they just THINK they do? And is "knowing" really important here? Is there light at the end of the tunnel? Why are we here? Do we exist or are we imaginary?...........................................................Is this all part of some plot..................................................Errr. Brain malfunction. Brain malfunction........................Going back outside to work on my cruiser now for some therapeutic repetitive paint-scr@ping activity. (Repetitive activity like chanting "Hari Krisha", banging your head against the wall, or scr#ping paint are known to sooth troubled-minds ya know.)

Oh, and thank you, again, for proving that you screen name could not be more accurate.


It would be fun to have a with you.

 

[slickrock]

OK I suck and fell asleep before uploading the picture for poser BUT!!!! . . . I did go for a longer drive today and started in town and worked my way up to the highway. Without the cup in there I had ZERO 0 NO brake issues. Rig stopped straight and true and now extra drag caused by brakes creating friction. When I pulled into the drive way, the were not hot and there was no squeaking sounds (of a brake dragging) while driving. I fell comfortable with the valve removed.

Sure, the only experience I had with the cup valve was driving up and down my street, but if it is working right now without it (and doing 2 emergency stops) I will leave as is.

Only funny thing is, I would have never installed this 60 series axle if I didn’t pull my knuckle studs in the drum brake axle because it stops just about the same as my 4 wheel drum brake but it did have less of that last second kick when the rig finally stopped at emergency braking with the disk brakes.