What size brake line to go with???

[fishinnutt]

I am redoing all the brake lines in my 71 Blazer and I see the line comes in two common sizes 3/16 and 1/4. I am not sure which one to use or rather which one is right to use in a rock crawler application. If there is some critical info missing and I am sure there is, let me know and I will fill in the details.

 

[owenst7]

If memory serves me correctly, 1/4 in is only used from the MC to the rear frame because that line feeds both rear wheels. 3/16" is all that is used for an individual wheel.

The front calipers take more volume though, so they might use 1/4"...you know it's been so long since ive fiddled with the hard lines I can't remember. I do know the rears are 1/4" until it drops to the axle, and then it's 3/16" after the T going to each wheel.

 

[496truck]

m/c to prop valve 1/4 (both lines)
prop valve to rear hose 1/4
rear hose to wheel cyl 3/16 (both lines)
prop valve to each front brake hose 3/16 (both lines)

 

[fishinnutt]

Thanks for the info, it came just in time for the latest catalog order.

 

[fishinnutt]

Does the proportioning valve have to have 1/4" fittings or is there a reduction that happens at the prop. valve temporarily? I haven't seen any proportioning valves mention being setup for 1/4" fittings. This is the valve that I am interested in and it doesn't mention what size fittings it is for.

http://www.jegs.com/i/Wilwood/950/260-11179/10002/-1?parentProductId=1284815

 

[496truck]

Well, that's an A/M prop valve. You can build it with whatever size lines you want to.

IIRC from my schooling... Using one 3/16 line to feed (2) 3/16 lines will give you a soft pedal. It doesn't change the output pressure but increases fluid flow (or something to that effect). So, when building your hydraulic system, a good rule of thumb will be to feed with 1/4 and split with 3/16. Does that make sense?

 

[fishinnutt]

Yes that makes perfect sense. So the above prop valve I linked can be fed with 1/4" line I would imagine?

 

[496truck]

It would be worth a phone call to them to verify but I think it should be good to go.

 

[fishinnutt]

Thanks a bunch for the great and timely information.