New Booster... Fluid Leaking.

[87Chief]

I put in a Brake booster and master cylinder from a 98 Cherokee in today, got the brake lines routed and all the mods needed to make it work.. I'm not sure if I'm supposed to use the stock Prop valve (right next to booster) or was I suppose to grab the one from the XJ?

 

If I could keep the old one (stock) what flare is needed for the brake line on the rear fitting? (towards the rear of the truck)

 

I might have done the wrong flare (double flare?)

 

Thanks.

[ftpiercecracker1]

I think you mean distribution block, this right?

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Its probably called both, distribution block is just what i have heard and use. :dunno:

 

 

 

 

Find a cherokee with non abs brakes and pull off the lines that go to the master cylinder. Ignore what is outlined, look at the Master cylinder. Do you see the brake lines running to the distribution block? Those are the ones you need, they are direct bolt on without having to do all the crazy bending by hand. I did this TODAY on my 90 eliminator.

 

As for flares, the ones going INTO the DB are double, the ones going INTO the MC, those are "bubble".

[87Chief]

Awesome! Thanks!

[ftpiercecracker1]

mistaken, the lines going to the DB are double flare.

[87Chief]

Ok, I re flaired my line. Still the same problem.. It is coming out from the connector ABOVE the line..

 

Example...

 

Wrong brake line size? 3/16" correct?

[ftpiercecracker]

Are you using the original fittings that went on the lines? or did you cut the new line and slide on different fittings? If there is play in the brake line even with the fitting tight you have the wrong fitting. Or your flare could be cracked, did you do the double flare?

[87Chief]

It is the original fitting for the mj DB and I did do the double flare

[ftpiercecracker1]

Something that would really help is a picture so i can see your exact setup, i have an idea of whats going on but a picture would help trumendously. What exactly did you reuse and what did you get from the JY?

[HOrnbrod]

I don't like reusing old brake lines except for emergency. The easiest way is to pull the new (used 96 XJ) master cylinder with the lines, pull off the old lines from the existing distribution block, then bend new 3/16" lines from the master to the block reusing the existing brake line fittings. All double flared.  Cake.

 

 

Hmm, I think my master cylinder has developed skin cancer.

[Keyav8r]

There'll probably be a chrome one on there tomorrow.

[HOrnbrod]

There'll probably be a chrome one on there tomorrow.

:yes:   No, I'll just break out the Dremel and polish her up a bit. 

[87Chief]

I have new lines. I just re used the connectors.. I did bubble flare the lines going into the master cylinder... are those supposed to be double also?

 

I don't think that would cause the fluid to be coming out of the connector

[HOrnbrod]

You used a 98 Master so IDK. I just matched the flares from the old lines into each new line. When working with flare nuts, it's a good idea to use flare wrenches to torque them down. They grip on four sides too so less chance of cracking/stripping it.

[87Chief]

Hmm should I try a single flare on the DB?

[ftpiercecracker1]

What did you get your brake lines off of?  Something i learned on this is that my MJ had much larger brake lines than any of the other jeeps i found at the JY, even though the fitting would still tighten down it did nothing to clamp the flare to the DB. I had to find fittings that matched my brake line dia.

 

I will try to take a picture to show you what i am talking about.

[87Chief]

I got new brake lines at the parts store.. apparently I have been doing double flares wrong... I'm going to have to rent the right tool and see if it will help. I think I have been doing single flares..

[87Chief]

 

The back connector... You can kind of see where the fluid was leaking..

[87Chief]

Alright guys, I'm about to give up on this.. I re flaired the line FOUR TIMES! It is still coming out of the same place.. Am I missing something with this master cylinder/booster? It is a 98-00 one, it is longer than the WJ ones.. Anyone help please. lol

[ftpiercecracker1]

Dude i'm sorry i'm not of much help, i don't know WTF is going on.  :(

 

 

I don't have much to offer but there can only be three things going wrong here, DB, Brake nut, or the brake line. Where the lines you bought pre flared?

[HOrnbrod]

Are you using a flare wrench to sock that nut down tight?

[maddzz1]

Are u using the little round flare piece to measure and make sure you don't have too much or too little brake line sticking thru the flaring tool before you start to flare. Too much or too little line will make the flare not press into the fitting properly and not seal right causing the leak.

 

Also, if you have a cheap flaring tool (like mine) and tighten it down too tight on the brake line it will warp the line causing a bad fit. Ask me how I know?

[87Chief]

I have done all those things.. I looked at how much thread is actually going into the DB and its not that much.. maybe 1 or 2 full threads.. I'm thinking my DB is stripped..

[HOrnbrod]

I have done all those things.. I looked at how much thread is actually going into the DB and its not that much.. maybe 1 or 2 full threads.. I'm thinking my DB is stripped..

If all your other new flares are not leaking, then I'd say that's a good possibility.

[ftpiercecracker1]

1 or 2 threads? I wish i had known that ahead of time.   :doh:

[87Chief]

Sorry I didn't even noticed... I guess its a new DB on the list