Brake MC question

['65 chevy lover]

I have decided to keep the drum brakes on my '65 for awhile instead of going disc. I have a new double MC with a booster. I'm also going with dual lines. Which line needs to go where? Does the front brake line need to hook up to the hole closest to the firewall or, the rear brake line? Hope this isn't a stupid question. Thanks for any help.

[slepysal]

read this :http://67-72chevytrucks.com/vboard/s...d.php?t=332148
Good write up It is an easy upgrade too.

[Captainfab]

Do you have a disc/drum master or a drum/drum master?

['65 chevy lover]

Originally Posted by slepysal

read this :http://67-72chevytrucks.com/vboard/s...d.php?t=332148
Good write up It is an easy upgrade too.

Thanks for the link!

['65 chevy lover]

Originally Posted by Captainfab

Do you have a disc/drum master or a drum/drum master?

The MC I have came with a proportioning valve and was intended to be disc/drum. I think all I need to do is remove the proportioning valve. Is this correct? Thanks for your help Captain!

[slepysal]

you can pick up the coreect one at CSK, Autozone or a local parts house for fairly cheep. Save the Disc/Drum master for when you do the disc swap, chances are you'll want to upgrade sooner or latter!

['65 chevy lover]

Originally Posted by slepysal

you can pick up the coreect one at CSK, Autozone or a local parts house for fairly cheep. Save the Disc/Drum master for when you do the disc swap, chances are you'll want to upgrade sooner or latter!

Good idea. I do plan to eventually change to disc/drum so, I'll buy the correct one and put the other one away for now.

Thanks for the help!

[Captainfab]

I agree. You will be better off with a drum/drum master cylinder.

Originally Posted by slepysal

you can pick up the coreect one at CSK, Autozone or a local parts house for fairly cheep. Save the Disc/Drum master for when you do the disc swap, chances are you'll want to upgrade sooner or latter!

['65 chevy lover]

I called POL where I bought the MC. Was told that all I had to do was remove the proportioning valve and use the MC as is. Questioned them about it. Tech said it was no problem. I'm a bit confused now. Is it possible that the tech is correct?

[Captainfab]

While that may work, it may not be correct, depending on just what master cylinder you have. With original style master cylinders, there are ones specific to drum/drum applications, ones specific to disc/drum applications, and yet others specific to disc/disc applications. This is in addition to the proportioning valves.

['65 chevy lover]

Originally Posted by Captainfab

While that may work, it may not be correct, depending on just what master cylinder you have. With original style master cylinders, there are ones specific to drum/drum applications, ones specific to disc/drum applications, and yet others specific to disc/disc applications. This is in addition to the proportioning valves.

I called back again and talked with head tech. He said if someone called and asked for a drum/drum MC, it would be the same. He better be right! Thanks again for your help.

[jocko]

I'd go to Oreily and spend the $15 on a drum/drum mc personally. Does your disk/drum mc have equal or unequal size reservoirs? If unequal, then do NOT use it for a drum/drum setup. Also, a drum/drum mc has internal non-adjustable proportioning built in due to the sequence in which the ports are unvovered when you push the brake pedal (whereas the disk/drum setup uses an external adjustable prop valve) - so I'd be wary of the tech's advice to just delete the prop valve and use the disk/drum mc. I'd be concerned you would lack the proper front/rear biasing if you use a disk/drum mc and no prop valve.

Here's another thread similar to chiefrocka's - he inspired my own dual res mc conversion.
http://67-72chevytrucks.com/vboard/s...d.php?t=461058

One note - whatever you end up doing regarding MC, I'd use a single part number purchased combo of mc/booster so that you KNOW you have the correct length intermediate pushrod (i.e. between booster and mc). In other words, try to avoid mixig and matching a non-power mc with a booster. Non-power mc's generally have a deep hole piston and boosted mc's have a shallow hole piston. I (personally) don't like to mix and match because I'd prefer a factory correct length short pushrod between the booster and mc. You could run into this dilemma if you do run down to oreily and buy a new mc only to add to your booster - so if you do, just make sure it is a POWER dual res master cylinder, that's all, so that it has the correct shallow hole piston (better yet - take the booster with you and make sure they fit together properly (correct length pushrod on the booster to interface with the mc, specifically) before you plop money down on the mc.

['65 chevy lover]

Originally Posted by jocko

I'd go to Oreily and spend the $15 on a drum/drum mc personally. Does your disk/drum mc have equal or unequal size reservoirs? If unequal, then do NOT use it for a drum/drum setup. Also, a drum/drum mc has internal non-adjustable proportioning built in due to the sequence in which the ports are unvovered when you push the brake pedal (whereas the disk/drum setup uses an external adjustable prop valve) - so I'd be wary of the tech's advice to just delete the prop valve and use the disk/drum mc. I'd be concerned you would lack the proper front/rear biasing if you use a disk/drum mc and no prop valve.

Here's another thread similar to chiefrocka's - he inspired my own dual res mc conversion.
http://67-72chevytrucks.com/vboard/s...d.php?t=461058

One note - whatever you end up doing regarding MC, I'd use a single part number purchased combo of mc/booster so that you KNOW you have the correct length intermediate pushrod (i.e. between booster and mc). In other words, try to avoid mixig and matching a non-power mc with a booster. Non-power mc's generally have a deep hole piston and boosted mc's have a shallow hole piston. I (personally) don't like to mix and match because I'd prefer a factory correct length short pushrod between the booster and mc. You could run into this dilemma if you do run down to oreily and buy a new mc only to add to your booster - so if you do, just make sure it is a POWER dual res master cylinder, that's all, so that it has the correct shallow hole piston (better yet - take the booster with you and make sure they fit together properly (correct length pushrod on the booster to interface with the mc, specifically) before you plop money down on the mc.

They appear to be equal. I'll check it out. The tech also stated that the rear brakes should go into the port closest to the firewall and front brakes to the front port. I thought it was the other way around? Thanks for the info.

[Sharps40]

Here is the drum drum split upgrade I did on Ol John Lee over Christmas.

Part numbers are on the photos...takes ya thru all four wheels, splitting and installing all new lines and the Al Cardone drum/drum master.

Everything worked good as new and still does, though Ol John Lee is in the garage due to being struck by an Uninsured unlicensed no english speaki aggressive driver last week.

http://67-72chevytrucks.com/vboard/s...d.php?t=558945

[jocko]

I'll be honest, I'm not certain the tech is correct. Some newer mc's are as he outlined, but our era trucks (and even the 67 dual res mc) was rear port to front brakes and forward port to rear brakes. And that was the only way the internal proportioning would work correctly. If you are going to use the mc you have, perhaps it would be advisable to use the prop valve anyway... At least then you can adjust. Only the tech knows the specs on what was sold to you - so I won't second guess him. But the routing he mentiones (which port to which wheels) IS different from the early dual res mc's.

[Sharps40]

On the drum drum master I used (67 C10 dual resevour $15) Rear drums go in the port closest to the radiator or the forward port. Front break drums go to the port closest to the firewall or the rear port.

[jocko]

Originally Posted by Sharps40

Here is the drum drum split upgrade I did on Ol John Lee over Christmas.

Part numbers are on the photos...takes ya thru all four wheels, splitting and installing all new lines and the Al Cardone drum/drum master.

Everything worked good as new and still does, though Ol John Lee is in the garage due to being struck by an Uninsured unlicensed no english speaki aggressive driver last week.

http://67-72chevytrucks.com/vboard/s...d.php?t=558945

sorry to hear about the accident - that stinks. one comment on your great thread, might consider the possibility of line abrasion on the last pic of post #5 in your thread - might be a good idea to wrap the line in rubber as it goes through that frame hole - you've got bare brake line rubbing against a metal edge that might wear thru in short order. Even if not affected by suspension movement, might be worth protecting it.

[Sharps40]

Originally Posted by jocko

sorry to hear about the accident - that stinks. one comment on your great thread, might consider the possibility of line abrasion on the last pic of post #5 in your thread - might be a good idea to wrap the line in rubber as it goes through that frame hole - you've got bare brake line rubbing against a metal edge that might wear thru in short order. Even if not affected by suspension movement, might be worth protecting it.

Thank,

Sorry, I just looked over the thread and a buncha pics are flat gone. Not a lot of help. I don't have the pics on the computer now but maybe somewhere else and I can rebuild the thread. Darn computers lost my pics and darn UUNESAD smushed my truck!

[Sharps40]

We'll work on that brake system again if we have to replace the frame. Otherwise, may have to replace the truck. We shall see, insurance companies and negotiating with em sucks.

[jocko]

Originally Posted by Sharps40

Thank,

Sorry, I just looked over the thread and a buncha pics are flat gone. Not a lot of help. I don't have the pics on the computer now but maybe somewhere else and I can rebuild the thread. Darn computers lost my pics and darn UUNESAD smushed my truck!

here's the pic, if that helps. Oh my Lord, I hope you don't have to replace the frame... Sounds like a bad accident.

[jayoldschool]

Doesn't the hose end go through that hole and get secured with a C clip from the other side?

Sharps40, thanks for that other thread, I'm going to do the exact same job on my truck. If you can get those pics working, it would be great!

[Captainfab]

Yes. That is the correct way to remedy that situation.

Originally Posted by jayoldschool

Doesn't the hose end go through that hole and get secured with a C clip from the other side?
Sharps40, thanks for that other thread, I'm going to do the exact same job on my truck. If you can get those pics working, it would be great!