Does the vac brake require reversing the brake lines

[turbo nasty]

Doing the swap and concerned.......The PM has the rear line for the front brakes and the vac has the front brake line for the front brakes.

Did a search and saw nothing about reversing the lines.

Does the lines need reversing?

 

[turbo nasty]

Bueller..bueller...Anyone????

 

[zeus87gn]

I would hope someone will correct me if I am wrong, but...

To my knowledge, every brake system has the line to the front wheels to the rear port of the master cylinder. Quicker reaction once you step on the pedal. It works first....a split second faster than the front port.

 

[pacecarta]

front port goes to rear (wheel cylinders) , rear port goes to front (calipers)

master cylinder, brakes, brake problems,

 

[turbo nasty]

Could have sworn on other line loc installs on vac brakes on other vehicles I used the front port(furthest fromthe firewall) for the install.

Just wanna be sure

 

[turbofish38]

Yes the lines are reversed between the PM and the vacuum.

 

[pacecarta]

1/4" hose is for rears , 3/16" for fronts
my 86 with vac brake is rears at front port, fronts at rear port ,


went and checked my 87 with PM ( its not the original one) and dispite beleiving it is wrong ,it is reversed of the vac brakes ... fronts at front port , rears at rear port

went and looked at another 87gn here with PM that was changed (at one time it was a manual M/C) , it has the rears at front port , fronts at rear port , right or wrong thats how it is now (i didnt do it)

I also looked at another 87gn here that i converted to vac and i dont recall swapping the lines when i removed the PM and now with vac brakes they are rears at front port , fronts at rear port (which is correct fror vac brakes), so maybe it was wrong before with the PM ??


now i have to do some documentation research

 

[pacecarta]

well heres GM's veiw of the PM install , which is indeed reversed of vac brakes

it shows fronts (smaller 3/16" line) to front port , rears (larger 1/4" line) to rear port

looks like the other gns i have here were backwards,

 

[turbo nasty]

Thanx to all for the for the replies

My PM and Vac Master cylinders have the big line in the front and smaller in the rear. I.e.- Same fittings/same placement on both PM and Vac.
Called Nick Micale and he said he has done countless and no need to reverse the lines.

Bottom line Its hooked up and all I can say is...........
HOLY SNIKEYS!! I have waaaay better brakes now.
I have the line loc installed on the REAR (closest to the firewall) port at the MC (not after the pro valve) and it works so the lines dont need to be reversed.
My Pm was rebuilt (internally) 3 years ago and accu, sw and motor was replaced at the same time with new. The switch was in need of replacement as of late and to be honest the parts are outrageous, so I gave the vac route a chance.
So far so good

 

[turbofish38]

Thanx to all for the for the replies

My PM and Vac Master cylinders have the big line in the front and smaller in the rear. I.e.- Same fittings/same placement on both PM and Vac.
Called Nick Micale and he said he has done countless and no need to reverse the lines.

Thats weird. I probally did the first vac conversion back in the late 80's. The lines are indeed reversed. It's no big deal. Just bend the old ones to fit. The two flair nuts are a different size. No way you can screw up the install.

 

[turbo nasty]

Maybe there was a change in design or something.
The lines were reinstalled exactly like removed not reversed.
And the line loc is at the MC before the pro valve.
So the lines are right.

 

[pacecarta]

i checked pics of 4 cars on ebay yesterday night, all 87s (some early some late prod) all powermaster and they all had rears at front port , front at rear ports, same as vac brakes

 

[POWERBRAKEBOB]

Hydroboost Conversion

In All Brake Disc Brake Masters,the Larger Reservoir Feeds The Front Brakes. The P/m Front Line Feeds The Rear Brakes, The Hydroboost/master We Use Has The Larger Bowl Feeding The Front Brakes. In Gm Cars, The 9/16" Thread Is For The Rears, And The 1/2" Thread Is For The Fronts.