The Stovebolt Site Forums The Shop Area General Truck Talk stock or upgrade master cylinder & bench bleeding master

I'm about to order a new master and don't know if I should order the direct stock replacement or should I upgrade to a better master (dual resevoir, corvette style, etc) while I'm at it? Now let me say I don't care to upgrade to disc brakes, and I am on a very tight budget- I just didn't know if there is a much better upgrade that is a direct bolt on master that I should get instead of the stock version. I don't want to complicate things by having to adapt a different master ya know.

I also would like if someone could give me a crash course on how to bench bleed the master. I've heard it's much easier in the long run. I did check the tech and the search but couldn't find much. Thanks for the help guys!

Id fix the original one if you are staying with stock brakes. Also when I rebuilt the one on my 53, it was much cheaper to have the thing re-sleeved than buy a new one.

I'm guessing we are talking about your 49 3/4 ton.

I would say go with the dual master cylinder setup and stock brakes. I think you would be very happy with the power brake version of it that virtually bolts in place under the floor. I say VIRTUALLY as it really requires a little bit of fabrication to make it work. In the long run it will be safer, allow you to stop faster, and replacement parts will be eazier to find. To my knowledge there is no disc brake kit offered for the 3/4 ton. Best you can do is swap out the backing plates from a later 50s truck and upgrade to the bendix brakes, without to much fabrication.

John

I should have said that I will swap the front for '53 1/2 ton axle and brakes and I found a 6 lug 60's rear end that I will put under there after I get the engine going. Is it simple enough to rebuild the master?

As far as bench bleeding the master cylinder, it's pretty easy and can be very beneficial if not crucial when installing a new master unit.

I started to type out some instructions here on how to do it, then I remembered where I had seen some real good instructions on it and figured it would be easier just to post a link.

This is a link to the Classic Performance Parts tech page

Scroll down the page a little to find the section you're looking for.

Good luck.

The original master cyl. is real easy to rebuild & the kit is not expensive. You will need to buy a brake cyl. hone. They are available at the Chinese tool stores for less then $10. Make shure there are no deep corrosion in the bore. A small amount will hone out & a slight discoloration is acceptable. If it won,t clean up you will need to buy a new one or get it sleeved. It is best to bench bleed it & get some Speedy bleeders.

Just my 2 cents.I would go with a dual cyl.One of the better ideas to come out of Detroit a few years back.Gonna cost a couple of bucks,but in my opinion it is money well spent.

I definitely agree with Dale on the dual master cylinder, unless you are hard core about keeping it original.

The small extra cost for a dual master may be money well spent. Someday that extra cylinder may be the only thing that keeps you and/or your truck alive should you have a leak somewhere in the system.

Thanks for the link "Bad Luck"! Are there any dual masters that will bolt right up or are they all gonna have to be adapted? I don't mind drilling new holes but I don't wanna have to make brackets and all. Are dual masters harder to get blead? If I do decide to rebuild mine and maybe have to resleave, where would I go for that- the local machine shop? Is it too obvious I know nothing?? I really appreciate the help!

Lazy J, this is the dual set up I purchased not long ago.

http://piratejack.net/index.php?pag...amp;option=com_virtuemart&Itemid=114

It bolted right up with no drilling or modifications.
Sure it was double the price of the stock but didn't seem to expensive.

I kept my original brakes for now because 3/4 ton issues.

I opted for the cylinder/booster upgrade to keep avenues open without throwing any money away. Im planning on upgrading to disk one day.

I needed all new lines anyway so I thought know is the time if custom fabricated lines was gonna be done.

Otherwise I might have just did the cheapest quick fix.

For those of you that have done a conversion to dual circuits, I have couple of questions (I HAVE searched the posts) on my '54 3/4 ton with drums all the way around;

1)Can the new master go in the same location as the original, and does this mean that you cut a larger hole in the floor?
2)What else needs to be modified (i.e. brake lines or pedal modifications.

Any help is greatly appreciated.

I have details and pictures of the conversion of my '54 GMC on my website . Click on "Front Suspension".

Thanks Cletis, I saw the pics and will try to work from there. I'd like to avoid the booster component.

I had taken the master off this weekend and busted one of the brake lines. I think I need to replace the lines anyway but is there a cheaper way other than ordering the entire set through Classic Parts or LMC? There's a pre-flared assorted length set on ebay that I'm thinking about getting. Also there's a line running from a splitter right out of the master up to the engine compartment but it's crimped off, do I even need that line? What could it have been for? Thanks!

Which master cylinder did you decide to use? If you use the dual master you won't be able to use stock brake lines. As far as ordering them off ebay, you can get them at an auto parts store without paying shipping.

You don't need any crimped lines on your brake system. Are there lines to all 4 wheels? Something is screwy here.

I think I'm gonna try to rebuild this one cause it looks to be in good shape. There are lines running to all four corners but someone (I doubt it's factory) had run a line up to the engine compartment but crimped it over but can't figure out what they had in mind? Is there anything factory that it would have connected to? I've seen the diagram in Classic Parts mag and the other lines look right except that line is not on there. Also which type of brake fluid does it take?

Also I think I want to get the speed bleeders. Does anyone know off hand what size I would need for 3/4 ton '49 brakes? Thanks for the help!

That extra line may have been for a brake light pressure switch. I just put in a new brake line system and it was easier to put in a pressure switch for the brake lights than to try using the old brake switch.

Frank