Reversed Brake lines?

[mr. fix it]

Hi there,

I was told the other day that I had reversed my brake lines at the new dual M/C setup.

I am using a 67 Dual M/C with drums all around.

Currently I plumbed it so the frt res feeds the front brakes & the rear feeds the rear.

I was told that I should have the front reservoir feeding the rear drums and the rear res. feeding the fronts brakes.

I understand that if this was disc/drums then the larger res would feed the front disc's and the smaller res feed the rears.
Again, I have drums all around

Any thoughts to confrim or dispute this?

 

[MrMoparCHP]

Correct, I have been told that it was for safety in the even of a piston failure, you'd still have front brakes.


Alan

 

[mr. fix it]

Interesting comment Alan. I have seen both ways now..

If I were to lose the seal on the piston for the front, I would still have rear brakes would I not? and vise versa?

The failed chamber would push through to activate the other system although scaring the day light out of the driver while they had to push the pedal a lot further than expected..

 

[MrMoparCHP]

No idea the reason, but when I upgradded my truck to disc brakes I found master cylinders with the larger reservoir in the front and the rear, the size of the fittings swapped as well.


Alan

 

[john66ny]

I would suspect that the "larger reservoir = front" advice was given with the thought that this would be the plumbing for a disc/drum system and should you convert in the future you wouldn't need to change it?

 

[1978 NYB]

Both my 78 Newport & NYB have the big chamber at the rear position.

 

[mr. fix it]

The rear chamber/res is larger for the larger amount of fluid required for disc brake pistons.

I agree if I ever upgrade to disc brakes that this is the way it has to be as well as installing a porportioning valve to balance the braking system.

 

[mr. fix it]

I could do this right away as well but then I have to change lines around and re-bleed the system...

 

[rexus31]

You'll know if the fronts or rears engage first if you get up to about 30mph and sharply hit the brakes. If the nose of the car dives immediately, the fronts are engaging first. If not, the rears are engaging first and you have the lines swapped. Based on your pic, it looks like you are a ways off from trying this. I've always been told the rear reservoir is for the front brakes and the front is for the back. The reason I was always told was the line attached to the rear reservoir will get pressure before the front when the pedal is depressed. Fronts brakes should always clamp before rears.

 

[mr. fix it]

Actually I used a photo from a month or so ago now to make it easier to see how I had plumbed the brake lines.
I have the car on the road now.
I am going through a break in period with the brakes. I only have about 30 miles on the car so far and thought I would post this question

 

[mr. fix it]

Strangely enough, I just found this on the web...

http://www.mbmbrakeboosters.com/ind...tent&view=category&layout=blog&id=8&Itemid=16

I have not heard about the 10psi valves before....but now having read the post, it is for systems where the M/C is below the level of the wheel cylinders...

 

[70bigblockdodge]

There should always be residual pressure valves on drum brakes this keeps the pistons out against shoes keeps pedal engagement higher. Should not be on disc system causes drag.

 

[mr. fix it]

There should always be residual pressure valves on drum brakes this keeps the pistons out against shoes keeps pedal engagement higher. Should not be on disc system causes drag.

Is it built into the M/C?

YES YES YES!!! the valves are.

 

[BJS racing]

Is it built into the M/C?

If you have the master mounted up on the fire wall there is pressure from gravity. And the rear chamber is for the front brakes as it will engage first.

 

[70bigblockdodge]

Yes, not the 10psi ones, but the 2 psi are normally in m/c sorry for any confusion

 

[mr. fix it]

So i reversed the reversed brake lines and now I can actually lock the brakes up! even with drum brakes..

I have learned a good lesson here..

 

[70bigblockdodge]

So works much better with lines on correctly?

 

[mr. fix it]

So works much better with lines on correctly?

Yes!
I left skid marks!!!

On thr road that is... in case you are wondering

 

[70bigblockdodge]

LOL. It would seem to not make a difference but there you go, it does!! Thanks for being a Guinea pig and glad brakes are working properly as to not leave skid marks somewhere else.

 

[commando1]

So works much better with lines on correctly?

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