The Stovebolt Site Forums The Shop Area Driveline 59 Stock Master Cylinder Fitting

Trying to get a '59 back on the road. On a stock style master cylinder should there be a fitting between the back of the master cylinder and the brake line that runs out the back to the first brass T fitting? Inline tube says it's a 7/16 24 tube nut but that is too small to connect to the master cylinder.

Thanks,

Michael Conrey
Germansville, PA

My truck is a '57 two ton, all of the steel lines are 1/4 inch, I don't think there is any bushing in mine - the main brake line threads directly into the MC. Is you line 1/4 inch?

I think you may need one of thease

Those are for wheel cylinders

It is 1/4" brake line and according to the 59 Shop Manual that size is correct.

Regarding the fitting kit suggestion, it looks like that one is only for cars, not the trucks and it moves the port location to the side which doesn't line up with my pre-formed lines. Out of curiousity I might order one anyway and see if I can make it work as a last resort.

I did find in the orignal parts book a listing for a 58-59 "main cylinder pipe adapter" pn 3739974 which might be what I need to find. I don't see anything on the usual parts suppliers websites for any special fittings for the 58/59 though...

Michael

It actually shows that fitting for the master cylinder on some Chevy cars.

Michael

Michael, I have NIB Task Force master, I can look at it in the AM and see what it looks like.

Ed

Take a look at this video by elderly iron. Looks like it may be like yours.

Yes it looks like Jeff (Elderly Iron) needed the same adapter on his 58 GMC. Fortunately he was able to swap it over from his old master cylinder to his new one. If anyone has a source for this adapter new or used please let me know!

I found this photo on Ebay of a sold used 55-59 master cylinder and it's a little fuzzy but you can see there is definitely a fitting between the master cylinder and the brake line tube fitting. The search continues.

I have about 50 trucks I am parting . Assuming this is for a 1/2 ton. Please verify . I will see if I have one.

Yes thanks ppp. This is for a 1/2 ton longbed.

Michael

Michael,

This is what mine looks like.

Ed

I agree that 3739974 looks like it may be the right part.

The first picture that EdPruss posted, looks like the female end of inverted flare. If all you need to do is get a single 1/4” tubing line adapted to the master, take the master with you (if you can), go to NAPA or another FLAPS and see if they can match it up.

The one in this image is not correct for trucks . That is for a car . The truck is more like a reducer .

Well I crawled under a few trucks . I do have one from a 58 1/2 ton . Shoot me a pm if interested . I can give you my phone for pics and or text .

I have been to three auto parts stores so far with no luck but it does look like I have a lead on a used one.

I also took a picture inside the master cylinder threads and my original (not the one in the first picture in this discussion) master cylinder looks a little different than Ed's. It doesn't look like inverted flare. Maybe pipe thread? Which would make sense to me since the threads needs to make a tight leak free seal at this point unlike the female side of the missing fitting which would be inverted flare.

The circular rings on your master look just like my master in my ‘52 1/2 ton. That would have a copper gasket compressed to make the seal. Not sure that would be pipe threads as mine were not and had a special fitting attached. I can’t say that yours would be plumbed like mine but like I said before it looks just like the end of mine.

We need a ‘bolter with a ‘59 1/2 ton to chime in and give us some pictures of not only the master but how its plumbed!