Dual line master into a single line...??

[ChiefRocka]

I have a question regarding a master cylinder. Well some of you have seen my "Project build". I'm getting ready to drop in the engine.

My question is this...Can I install a dual-line brake booster/master into the truck..and 'T' both outputs into the single line brake system of the truck ??

Eventually the brakes themselves will be done...but for now, I could get this part done of the brake system done.

I have a brand new booster/master that came of a totaled 76 Cutluss.

Now that the engine is out, and the hood is off...it would be alot easier to fab the mounting for it.

The current master is working, but it's leaking out the rear seal, and I have this other one laying here.

Ya thing it'll work ??

Thanks...

John

[62 short step]

I dont see why not?

[62 short step]

Your not going to put a proportion valve on right? I'm assuming you have all drum brakes on your truck?

[Jonboy]

The onlything that might be a problem is the cutlass master has one reservoir a lot larger than the other to operate the disc brakes. I would be afraid the piston would move a lot more fluid to the front. I would bet the original master would bolt up to the Cutlass booster, so you could go through all of the trouble to mount it, and just bolt up the new master later. Or, since you have the engine out, that might make it a lot easier to mount and route all of the new brake lines in the front. What brakes are you going to use?

[slepysal]

hey Chief , why not fab up the lines now? If not I would try split the front/ rear brakes.

[mnky30]

what about your clutch is it fluid or cable driven

[Fred T]

A couple of good points on the m/c setup for disc brakes. If this m/c is set up for front discs and you have front drums and you split the lines you will need an adjustable proportioning valve to balance the brakes. If you split and have front discs a stock valve will work.

Does the m/c have a large reservoir for the front brakes? If so, and you have stock drums all around, you could try using just the front reservoir. I don't know what the piston sizes on either m/c, this affects the line pressure. But if you want to hook it up and see how the brakes work, it might work.

Connecting the two bowls together when the m/c is from a disc/drum system will cause problems due to the pressure difference unless and adjustable proportioning valve is used.

[ChiefRocka]

Well you all have very good points.

Slepy, your right...I should split the lines now....it's just that this dam project is drag'n along.

So could I just plug the smaller port ??

Well see how it goes...I might just buy some line and go for it.

Thanks guys for the suggestions !!!

John

[ChiefRocka]

By the way..I'm running DRUMS all the way around untill I build up my suspension.

I just replaced all the drums, cylinders, shoes and hose. So it'll be good for a while.

I just wanted that part done since it was easy accessible

John

[wild one]

Hey John, thought that I'd throw in my .02 on this one. When I did the conversion from drums to discs on my 66, I bought a master cylinder from Monument Car Parts - my local parts house - spec'd out for a 71/72 C10 truck. The funny thing was, is that the same master cylinder is used for discs OR drums - both reservoirs are the same size!

I found this out when I asked to confirm that I was getting a master for discs (they only wanted $40.00 for a NEW master cylinder) and not one for a drum brake application. I was then told by the counterman that both applications called for the same application. After getting the part in my hands and looking at it the guy (former GM parts department salesman with 30+ years in the field) said that alot of the earlier disc brake masters that GM used were also used on drum equipped vehicles - hence the same sized front and rear bowl sizes. The only part that was different was the proportioning valve - one for discs, one for drums.

Hope this helps,
Pete

[rodnok1]

I wouldn't plug any m/c ports...You really should hook them up to both front and rear seperately. If for no other reason for safety. If you were to tee them together you would cause all kinds of havok, since the two cyl apply diff amounts of pressure.

[ChiefRocka]

Wild and rodnok...Thanks !!!

I didn't think that plug'n a port was a good idea....I guess I'm just gonna buy some line, and make it up my self. I have a nice double flaring kit...might as well use it, instead of just for -8 Hydro lines !!!

Thanks fellas

John

[ChiefRocka]

Also anyone need one of these ?? It's your free, just pay the couple bucks for shipping !!! It's new, as well as the Alternator that came in my truck. Both in good working order. FREEBIES !!!



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When I got the truck, someone must of changed it out before letting the truck sit.


Anyone ??

John

[ChiefRocka]

Well I just realized that it's a NEGATIVE on using the Cutluss booster...It has an angle cast-aluminum mount that is riveted to the housing. Now the Master in-self I can use. It has the Large bowl in the front, and the Small bowl in the rear.

The front port is smaller then the rear port (fitting size)

Now which port is the front brakes ??

John

[wild one]

Large bowl, small port for front brakes - Small bowl, large port for rear brakes.

[ChiefRocka]

OK...I decided what to do....Bought a new dual-line drum master...and split the lines....

See those progress pics on my "Project build" thread....

John