The Stovebolt Site Forums The Parking Lot Big Bolts GMC 630 Master Cylinder

Hello,

I am looking for a part number for the master cylinder on my GMC 630-50. The maintenance manual I have for the truck only lists MC bore of 1 1/2". The original out of the truck is too rusty to read any numbers on it. Any help would be appreciated.

Thanks in advance.

Alex

Some photos:

MC 1

MC 2

MC 3

Hope you get an answer, cuase I need the same for my 54 630. Ron

Hey Alex. What engine do you have in yours?

cff, It has the GMC 503 six cylinder, what do you have?. Also has a hydrovac in case that helps anyone.

MC's for this era truck are very hard to find new, however they can be sleeved and rebuilt with a NAPA kit in most cases.

Mike B

Are the NAPA kits standard based on bore size?

I got the MC disassembled tonight. I did not find any pitting. What are everyone's thoughts on honing the cylinder?

If the bore is clean all the way out then I might make a quick pass with the hone just to make sure there are no low spots and to clean up the bore area that is outside of the pistons normal travel area.

Then buy a new kit and put it back together...

Mike B

Alex. Mine is the 503 also. Pretty cool engine. Mine is an old fire truck. Ron

Ron, mine is also an old fire engine from Baltimore City. Does yours have any special options? For example my truck has a syncro 5 speed OD trans, a locking rear, the doors don't lock, and the key is pinned in the ignition. I would like to see some pictures of yours.

Here's mine:

http://s1061.photobucket.com/user/abhadurihauck/media/IMG_0127_zpsbba7f0aa.jpg.html?sort=3&o=18

And when it was new:

http://s1061.photobucket.com/user/abhadurihauck/media/Engine23_zps9def5d21.jpeg.html?sort=3&o=10

I also have a '54, someone replaced the bed and pump w/ a flatbed and U-joint hangar, 503 w/ 5 speed synchro, need PTO for box, drove home to Denver area from Al, brakes take 4 pumps to work may need hydrovac? Repair. 503 works fine, 6 to 9 MPG on way home, 6.5 rear ratio, needs 4.8 or so.

Made up electronic ignition so far, not installed yet, Deve's mod. Thinking about fuel injection in the future, want to keep gasser.

Ed

Hi Alex. Sorry about taking so long to get back to you. Just started back to work today and hadn't been checking the computer at home. Busier at home than I am at work LOL.I live in BC Canada and I bought the truck in Idaho. I got it back to Lynden Washington and I had leave it there till I got my paperwork in order.Hope to have it back here on the 10th of Dec.I have a few pics,on my phone, but I don't know how to post them here. If you give me your email I do know how to email them from my phone. Don't know if the tranny is syncro or not. It is a 5-spd.Needs a master cylinder, so I trailered it from Idaho.Mine is a General also.

Hi Ed. Hey that's a lot better mileage than I thought it would get.That's 7.5-11.25 on a Canadian gallon. Any Pics?

Love the pics of yours Alex. And Ed, what is the Deve's Mod electronic ignition.

The Wagner part number for the master cylinder is 3374 1-1/2" bore the kit number is 11310 hope this helps.

Marv.

Marv,

Thanks for the MC info.

I don't know to post px either, send me your email via pm and I'll send some.

When someone replaced the pump with a carrier bearing and new driveshaft(s). (Good) They must of have lost the 16" Tru-stop brake disc, so, some true genius replaced it with a 14" one which wore a 14" groove in one of the shoes, hard to release, also. Luckily, in my junk, I have a 16" disc so when it warms a little(14F this AM) I'll swap and reline the shoes.

Ed

Deve@speedprint.com

Ed

Hi Ed. My email is ron.brightman@fraserhealth.ca, Ron

Ron,
Just sent px.

Ed

Marv. I have tried to find that wagner part number for the master cylinder, but no luck. I have a counter guy at O'reillys trying to find something, but no luck yet with him either. Where did you get that part number? Ron.

Ed. I didn't get your email with the pics. Are you sure you copied my email address exactly? Ron

OK guys, I found some on eBay, FC-11310. I ordered one, for $20. I figured it was worth a chance, they have some more. It looks just like a normal ms rebuild kit, 1.5" dia. In original, sealed box, no rust. Good luck.

Ed

Hi Ed. Did you get yours yet? If so, does it look like it's going to work? I think I'll buy one anyways. It's only $20 and if it doesn't work, I'll display it on a shelf in my shop. Ron

I got it, measures 1.5" OD, haven"t taken MC out yet. Looks nice, clean, no rust or corrosion.

Ed

Ed,

Did the ebay rebuild kit work out?

Alex

I don't have the mc apart yet, probably be a while.

Ed

Got the mc out, clean as a whistle. The mc repair kit((FC-11310) I got fits perfectly, no spring though. So, if you have not gotten one for yourself, go ahead. By the way, no auto parts places could find that part number, an IHC truck place found it on EBay.

I do not see anything wrong with mine to cause it to take 4 pumps to get solid brakes, I was hoping it would be a clogged feed port, so after I put it back together and it still does not work, I'll go through the hydrovac.

Ed.