The Stovebolt Site Forums The Shop Area Driveline Brake line junction block

Hello,



I am replacing the brake system (shoes, cylinders, lines, etc.) on my 54 Chevy 3100 1/2 ton truck. Someone has done work on the truck before so there are times when I'm not sure what is original or not.

In evaluating the current brake lines there is a junction block (T) on the front right frame (one line comes from the master cyl, one line goes to the front right wheel cylinder and the other to the rear).

Yet, I have checked with 3 online parts stores (Inline Tube, American Classic and Car & Truck) and they don't carry this part.

I ordered the pre-bent lines so I'm waiting to receive them to figure out how they should go in.

Does anyone know if the original truck came with that T-Block and if so where I might find a replacement? The lines I'm using are 3/16.

Thanks in advance,
Victor

Depending on what will fit in the 54 (or what can be modified to fit), you should find it here: http://www.jegs.com/p/JEGS-Performa...Fittings-for-Hard-Lines/1403915/10002/-1

Jon

** My 52 is exactly as you describe yours. **

My 51 1 Ton is the same. I did not replace my junction blocks. They are brass and don't rust. I did make sure they were clean.

...and my 52 panel has that same brass "T" block as the original poster described. Clean it up and it should be find.

Hi Victor, I have had good luck cleaning up the brass and putting it right back in service. Out of curiosity what type of fluid are you planning to put in the truck when you're finished?

Joe

Thank you all for your quick and helpful responses:

Jon G - Thanks - I called that business and they don't carry this specific fitting with the ability to bolt it to the frame.

Thank you Marzach and others for confirming on your trucks.

Thanks AmtrakJoe, Truckernix and Achipmunk for that option. May be a dumb question - Any guidance on what you used to clean it?

In considering the re-use of the existing junction block - the current set up looks like it has a larger line for the run from the block to the Master. Smaller lines that run from the block to the front and rear.

When I ordered my lines, they told me they are all 3/16 but they won't tell me what the thread sizes are on the fittings. It seems to me the issue is less about the size of the line vs. the thread sizes on the line fittings. Is that a correct assumption?

Thanks again for all of your help.
Victor

Hi Joe,

I did not have a specific fluid in mind. Do you have a recommendation?

Thanks,
Victor

panchos, your right. Quarter inch to the fitting and then 3/16 each way to front and back.
By cleaning I simply wash out the fitting hole's and brush up the brass on the wire grinder. Clean/blow it out good making sure the threads are good and clean. Don't use anything with silicone in it around the brakes.
DOT 3 brake fluid is good. I think my current bottle has DOT 4/5 on it and is synthetic. Do not use silicone fluid and don't ever let it contaminate what you have....or if you go silicone don't get it mixed with the regular stuff.

Most brake lines, if you buy them local, will have a paper tag on them stating they are either Standard, or Metric. To be sure what you were sent I would just try the brass block on the ends first to verify the sizes match...... a nice "thread guage" is handy to have around the shop to tell you what the size/threads are on stuff.
Just My opinions....

My 49 had 3 of those "T" blocks, one at the master cyl to main line junction, one on the frame at the right front wheel and the last one at the rear where the soft line to the axle goes.

I cleaned all of them up and reused them. I also ordered the prebent hard line kit and mine fit perfectly, which surprised me.

Had to chase down several small leaks but once I had all the connections good and tight and the shoes properly adjusted the brakes pumped up as well as Hucks will

10k miles later it's still stopping and holding it's fluid
Good luck
Dave

Went through this. This particular right front junction block is the only junction block that is not reproduced anywhere. You would need to find another original if you want to keep the stock setup.

By the way, the weird stock setup - separate tube for front left, other three wheels through this junction - would have to be changed if you you went with a dual cylinder.

Thank you for your recommendations and helpful information.

I will post an update on how the whole job went after I'm done.

Thank you Wurlitzer 46. I was planning to clean-up and re-use the one on the truck now from recommendations made here. A friend of mine also had a spare so we cleaned it up and have it as a backup. After calling many stores and not finding it new - makes sense or confirms what you're saying.

Bad news though on this project - I was driving my truck to a friends shop where I was going to re-do the brakes. Truck started vibrating something fierce. Stopped, checked underneath but did not see anything obviously wrong. May be a drive line issue (had a similar issue last year).

Hey guys, this may be what your looking for. It says for the frame rail for the years we want but it doesn't say "exactly" the sizes. A phone call should be in order if needed.
The Filling Station
http://www.parts123.com/parts123/yb.dll?parta~dyndetail~Z5Z5Z50000014a~Z5Z5Z510647~P29.50~~~~S4DO12ZH4724158723050V~Z5Z5Z5~Z5Z5Z50000014x

copy link and paste it..

Here ya go Alvin............

Brake Line Fitting Link

As Joe says Alvin,
That's the one,
Basically a "tee" with a mounting stud to go thru the frame rail.
regards and
Happy Fathers Day, DADS!
steve sr.

Hope Panchos54 checks back in. Thanks Joe, don't know what happened when I pasted the link?

.....I just wanted to show those blocks ARE out there.

.
.
i made my own system vic,

Bending 3/16'' brake line or for that matter 1/4 or 5/16'' BIG line isn't ALL THAT DIFFICULT.

I measured up all my pieces, went to a brake shop and they double flared the cut ends. i bought surplus screen door springs and stretched them to cover for flying rocks protection of my lines. joined them all together. everything is tucked away and protected. I bled my brakes. new master cylinder and front dics.
one junction at the front drivers and one at the rear passengers. my master has a cross feed / proportioning valve to operate the front at a different rate than the rear.

inspection hole at the filler top in the floor. held to the frame by 'jack nuts' and cushioned hose clamp w/ eyelet.
https://topscrewmetalcorp.files.wordpress.com/2013/08/blind-jack-nut-series-5-topscrew.jpg

http://s67.photobucket.com/user/1951otter/media/579990-R1-012-4A.jpg.html?sort=6&o=343

http://s67.photobucket.com/user/1951otter/media/579990-R1-018-7A.jpg.html?sort=6&o=342

http://s67.photobucket.com/user/1951otter/media/579990-R1-024-10A.jpg.html?sort=6&o=341

http://s67.photobucket.com/user/1951otter/media/579990-R1-016-6A.jpg.html?sort=6&o=346

http://s67.photobucket.com/user/1951otter/media/2748800-R1-045-21.jpg.html?sort=6&o=279

http://s67.photobucket.com/user/1951otter/media/DSC00366.jpg.html?sort=6&o=357

http://s67.photobucket.com/user/1951otter/media/91710005.jpg.html?sort=6&o=332

http://s67.photobucket.com/user/1951otter/media/2748800-R1-045-21.jpg.html?sort=6&o=279

http://s67.photobucket.com/user/1951otter/media/2748800-R1-047-22.jpg.html?sort=6&o=278

http://s67.photobucket.com/user/1951otter/media/DSC00493_0007.jpg.html?sort=6&o=259

Hello,

Again, thank you for the additional references:

I was able to find what I needed.

Achipmunk - The picture in the link is exactly what I was looking for. In the link and description it excludes my truck as it is 1/2 ton. (1951-55 (1st Series) Truck (except 1/2 ton)

Carolines truck - Thanks for the pictures, those were very helpful.

Hello,

I have another question. At the end of the master cylinder where the tubes split to go to the left front tire and the other across the frame to the junction block, is that a part that you all recommend be re-used? It didn't come with the master cylinder and I can't seem to find that part either.

Thanks again,

It was a while ago and I am a little hazy but I believe I bought one of these junction blocks - same as Jim Carter MEE 247. The vendors list the application as "1951-55 (1st Series) Truck (EXCEPT 1/2 ton)". If I remember, that part has three 1/4" holes, but the stock junction block on the 52 had one 1/4 hole in the center, and two 3/16 holes on the sides.

Carolines truck: that is a great modification. What size is the line from the master to the front junction block? Then what size from junction to each front wheel?

Pancho: The fitting on the end of the master cylinder is available from the vendors: