Brake line coil off master cylinder necessary?

[earl84]

I am redoing all my brake lines in conjunction with adding a Wilwood master and proportioning valve. Question is whether or not the coils are necessary or not that are generally right off the master.

I know GM did it on most stock trucks, but I see a lot of trucks without them. I want to do some different routing to clean things up a bit while I’m at it, and don’t really want to do the coils. If they are necessary, I assume thy should be horizontal instead of vertical so air can’t get trapped in the top part of the coil.

[mongocanfly]

The coils allow for flex between the body and frame...I used -3an ss hoses on mine to eliminate the coils..

[earl84]

Thanks for the reply. I think I am going to stay with the double flare 3/16 line. Broke the freakin’ double flare die today, so I am on hold anyway. I see so many clean lines run, like TheSub, OMGosh, that engine bay is insanely clean. Mine is nowhere near that, nor will it ever be, but I try to clean things up as I go.

[mongocanfly]

those fittings I used are double flare to -an....nothing wrong with using the coils though

[damnyankee36]

I don't know how the trucks were assembled but for Camaros the master cylinder was attached to the brake lines and left unsupported when the subframe was assembled. Only the two brakes lines held it up. The coils allowed for movement of the master cylinder without damaging them. When the subframe was attached to the body it was then bolted to the firewall or booster.

So, to answer your question, I would say it's not absolutely necessary to include the coils. There is negligible movement between the body and frame. I believe a little bit of slack in the lines wouldn't hurt however, mostly to make it easier to connect or disconnect the lines at the master cylinder.

[Keith Seymore]

Originally Posted by damnyankee36

I don't know how the trucks were assembled...

Trucks used a temporary master cylinder "slave" bracket on the chassis line to support the assembled system until it was attached to the front of dash. The slave bracket was then removed and recycled back to the installation point to be reused.

The brake system is completely evacuated, filled and function tested by this point.

K

[The Rocknrod]

Not needed.

[damnyankee36]

Originally Posted by The Rocknrod

Not needed.

Hey Chief. Off topic but I think your'e gonna like the 11" booster. Mine is a 9" and I have to stand on pedal a little too much for my liking. That's what was offered from CPP so I didn't question the size.

[The Rocknrod]

Originally Posted by damnyankee36

Hey Chief. Off topic but I think your'e gonna like the 11" booster. Mine is a 9" and I have to stand on pedal a little too much for my liking. That's what was offered from CPP so I didn't question the size.

That's a bummer for me. I just bought a 9" chrome unit. Maybe I should sell it and get a 11" in chrome one.
I was thinking about going all chrome instead of all Yellow zinc in the engine compartment...

[damnyankee36]

Originally Posted by damnyankee36

...Mine is a 9" and I have to stand on pedal a little too much for my liking. That's what was offered from CPP so I didn't question the size.

Off topic again to clarify/correct my post...

I didn't realize that the reason I didn't have good power assist was not because of the size of the booster, it was the fact that the vacuum port I used on the 1" carb adapter was a blind hole. It was never drilled to expose it to manifold vacuum!

I didn't have poor power brakes; I didn't have any at all! I have since then attached the booster to the carb port.

[Chevy Fleetside]

I have been running like this for 2 years now. I used a coupler so I could use my original brake rod with the later model power booster. There is a locking nut on there, you just can't see it.

[demian5]

Its a non issue, makes for easier mast cylinder replacement though...

[dracko]

No coils and no issues so far.

[1966 K10]

Originally Posted by dracko

No coils and no issues so far.

Looks clean. What year MC did you use? No warning switch or proportioning valve?

[dracko]

Originally Posted by 1966 K10

Looks clean. What year MC did you use? No warning switch or proportioning valve?

I think its for a ‘71 non-power disc/drum c10. I used an early 80’s prop valve with warning light switch, mounted under the fan shroud like the square bodies.

[sodly]

Originally Posted by dracko

I think its for a ‘71 non-power disc/drum c10. I used an early 80’s prop valve with warning light switch, mounted under the fan shroud like the square bodies.

I was curious about that master cylinder, too. Do you happen to know the exact brand/model? I like how it's more square and looks more like the old, pre-60s style/shape. Seems smaller than the later style too. It's a little less obviously out of place that most. Wondering where you found that one. Thx.

[The Rocknrod]

Originally Posted by sodly

I was curious about that master cylinder, too. Do you happen to know the exact brand/model? I like how it's more square and looks more like the old, pre-60s style/shape. Seems smaller than the later style too. It's a little less obviously out of place that most. Wondering where you found that one. Thx.

Are you going Disc/Drum? or 4 wheel disc?

[bloo]

As others have mentioned, the coils are there to take up motion between the body and frame. Yes, you can get by without, just pay attention to the motion. See how in The Rocknrod and dracko's pictures the lines go way over toward the driver's side and come back? It spreads the motion out over a whole bunch of line. That is more or less what the coils do.

Here's a disc brake conversion done in the 80s:

[Warrens69GMC]

That master is like this one at AutoZone

NM1494

https://www.autozone.com/brakes-and-...03_0_2558_2867

[The Rocknrod]

If your dyslexic.

[bloo]

Yeah, the rear brake reservoir is in front.

It looks like the same casting as the one I posted. The fittings are appear to be a different size though. IIRC it was for a mid 70s Ford van or truck (1978 econoline?). Disc/drum, 1-1/8" bore.

[dracko]

I got it from rock auto. Raybestos MC39177

[rvrfoot]

cpp on mine.

[The Rocknrod]

That's sweet right there.

[damnyankee36]

I went as far to as to recreate the factory coils.

Lots of ways to go about this...