Convert 1/4" brake line to 3/16" -- which adapter fittings do I need?

[crakarjax]

I'm ordering a 25' roll of 3/16" tubing to do my brakes and want to convert the old 1/4" to 3/16" so I can just use the same line from my roll all the way.

Anyone know which fittings I will need to do this conversion? It's for a '72 LWB coil truck with 12-bolt rear. I know that the 1/4" only goes from the master to distribution block on the diff, but have no experience with inverted flare fittings so I'm at a loss. TIA!

[min]

you can get an adapter at most auto parts stores. it has a 1/4 male end on one side and a 3/16 female end on the other side and uses the standard 3/16 inverted flare fittings. can get a picture of one for you tomorrow if it will help.
do you still have drum brakes in the rear? if so the 3/16 line may not work. drum brakes need more fluid to work than discs. could be wrong maybe someone else will chime in on that. just getting back into this after a 15 year brake and have forgot a lot.

[crakarjax]

Originally Posted by min

you can get an adapter at most auto parts stores. it has a 1/4 male end on one side and a 3/16 female end on the other side and uses the standard 3/16 inverted flare fittings. can get a picture of one for you tomorrow if it will help.
do you still have drum brakes in the rear? if so the 3/16 line may not work. drum brakes need more fluid to work than discs. could be wrong maybe someone else will chime in on that. just getting back into this after a 15 year brake and have forgot a lot.

I'm only on a 3 year break and I've already forgotten a ton as well... forum posts seem to indicate that 3/16 will work for rear drums (yes I have rear drums) and anecdotal evidence is that newer vehicles with drum rears have 3/16 line to them. The pressure will be the same, with potentially lower volume. But, the lines on the axle are 3/16 anyway so I'm really not worried about it -- and I'll probably upgrade to rear discs in the future anyway.

Thanks for the tip, does that adapter nut just seal itself onto the 1/4" flare and then the 3/16" line/nut seals into the adapter nut? If so I think I know what you are talking about. I haven't checked out a parts store yet, I was trying to find everything online first in order to minimize my trips to the store.

[SHANE 73Z]

If you are bending/flaring your own lines out of a coil, I would suggest getting the proper flare nuts & eliminating the adapters.

Typical flare nut sizes are:

3/8" nut for 3/16" line
7/16 nut for 1/4" line

Many of the line companies offer a 7/16" nut with the smaller thru hole for 3/16" line.

Inline Tube, Right Stuff Detailing, etc should be able to fix you up.

Shane

[crakarjax]

Originally Posted by SHANE 73Z

If you are bending/flaring your own lines out of a coil, I would suggest getting the proper flare nuts & eliminating the adapters.

Typical flare nut sizes are:

3/8" nut for 3/16" line
7/16 nut for 1/4" line

Many of the line companies offer a 7/16" nut with the smaller thru hole for 3/16" line.

Inline Tube, Right Stuff Detailing, etc should be able to fix you up.

Shane

Yeah that makes sense. You mean like this one? I thought that the 3/16 line wouldn't seal correctly to the 1/4" orifice but it must if they sell that fitting.

Those nuts are expensive, I think I'll just buy the 1/4" tube after all and then I'll have a bunch of tube left over that I can use later.

Well... maybe not. haven't made up my mind yet

[SHANE 73Z]

There are several ways to skin this cat.

That is what I was referring too. Once again, if your are bending your own you gotta put something on the ends anyways.

Just a suggestion, good luck.

Shane

[Mr Handy]

If your going through the trouble of bending the lines, I would not skimp on the right fittings, new fitting will not seem that expensive when you have the right ones and everything is how it should be.

[min]

Originally Posted by crakarjax

Thanks for the tip, does that adapter nut just seal itself onto the 1/4" flare and then the 3/16" line/nut seals into the adapter nut? If so I think I know what you are talking about. I haven't checked out a parts store yet, I was trying to find everything online first in order to minimize my trips to the store.

yes that is how it works. i tried to get the 7/16" fitting for the 3/16" line but they did not have it but said they had an adapter that would work. here is a pic of it installed.

[crakarjax]

Yep, you're right I'll just order the fittings and be done with it. Quick question though, I'm trying to figure out how many of the reducers I will need and I'm coming up with 4 -- does that sound right?

I have:
- 1 at the diff
- 1 coming out of the prop valve heading to the rear
- 1 going into the prop valve
- 1 coming out of the MC

[SierraMtns]

Originally Posted by crakarjax

Yep, you're right I'll just order the fittings and be done with it. Quick question though, I'm trying to figure out how many of the reducers I will need and I'm coming up with 4 -- does that sound right?

I have:
- 1 at the diff
- 1 coming out of the prop valve heading to the rear
- 1 going into the prop valve
- 1 coming out of the MC

Any updates on your brake lines? How did they come out?

[crakarjax]

Originally Posted by SierraMtns

Any updates on your brake lines? How did they come out?

Hey sorry I missed your reply... I'm actually just getting to the lines now! I'll post a complete list of flare nuts when I'm done but I can tell you that I'm already a bit short. For some reason the 1/4 to 3/16 fittings I bought don't seem to fit, even though the specs say they should. These are the ones I purchased http://m.summitracing.com/parts/gar-j9011

I've also attached a pic that I found helpful.

[crakarjax]

Ok so the fittings I mentioned above are correct -- but they are chrome plated and so a bit big, but they fit with lube and persuasion.

My list of inverted flare fittings:
4 - 3/16 OD x 7/16-24 reducer
2 - 3/16 OD x 1/2-20 reducer
2 - 3/16 OD x 9/16-18 reducer
3 - 3/16 OD x 3/8

This covers the stock MC, prop valve, four corners and rear flex hose dist. block. Couplers and tees will just require additional standard 3/16 OD x 3/8 fittings.

All of these fittings can be found pretty cheap at advance auto
http://shop.advanceautoparts.com/p/a...2F16+7%2F16-24
http://shop.advanceautoparts.com/p/a...c-5/22190119-P
http://shop.advanceautoparts.com/p/a...c-5/22190118-P