Damn brakes.

hjpcummins · Feb 7, 2016

Well iv been fighting brake issues from the get go on my new setup (ls,auto,tons w/disc)

Long story short.
Started life with an 89 cherokee bosster/MC
Very little brake pwr. 3-4 pumps to stop.
Swapped out for 96+ booster to try to resolve my issue.
NOPE.
Swapped for 96+ MC
Still nothing.
Iv bench bleed everything, iv bleed the system 2 dozen times. Still having to pump 2x for basic brake pwr on flat ground.

Swapped back to 89 booster/mc for simplicity (brake line routing)

Everything is connected, bleed, no leaks all new parts. (Besides front SD calipers)

At this point I'm willing to go with full manual brakes but making sure their isant a simple fix before I go this route

Tha nks

tiny · Feb 7, 2016

You don't have big enough bore on your mc. Think about how small the pistons are on the brake calipers and wheel cylinders of the Cherokee. Now think about how much bigger the pistons are you are using. You didn't say anything about your rear brakes. I imagine they are 1/2 ton Chevys.Try using the booster and mc off the super duty.

dmtfabrication · Feb 7, 2016

http://ssbrakes.com/i-10094036-brake-pressure-gauge-kit-sure-stop-a1704.html

Get one of these kits. I bought one to help diagnose why my CNC dual MC setup wouldn't give me the results I wanted. Years ago I read a BillaVista article that was called the Brake Bible (I think that's the name) http://www.pirate4x4.com/tech/billavista/Brakes/ He gives some formulas that are helpful (and complicated)

I think the goal PSI in the average caliper is 1500 PSI, I was barely getting 900 in my front Chevy D60 calipers, 1400 in my D44 calipers on the rear 14. I could lock and hold the rear, never the front.

hjpcummins · Feb 7, 2016

Re:

I've seen the ram 2500 and e350 upgrades but the info is wish wash. My firewall is cut for jeep booster patern. Is the bolt pattern pretty generic?

onepieceatatime · Feb 7, 2016

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I used a corvette master cylinder but can't remember what year. Something from the 60s I believe. Was available at the parts store and cheap.

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Jduck · Feb 7, 2016

The 2500 and e350 mc bolts up to the jeep boosters. May have to drill or egg out the holes a little

hjpcummins · Feb 7, 2016

Re: Re:

onepieceatatime said:
I used a corvette master cylinder but can't remember what year. Something from the 60s I believe. Was available at the parts store and cheap.

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I also seen this, for (4 wheel disc) manual brakes.

Thinking of ditching the power setup for manual. I'm over running back and forth to parts store since iv got a dozen trips wrapped up in this so far.

hjpcummins · Feb 7, 2016

Re: Re: Damn brakes.

Jduck said:
The 2500 and e350 mc bolts up to the jeep boosters. May have to drill or egg out the holes a little

Any paticular years?
And my setup is old. Ports on right side, either one have same?

jccarter1 · Feb 7, 2016

I think mine is a 2001 dodge 2500 and you will need adapters bc the dodge stuff if metric but it works like a charm I can lock down 43s and yea the hole need to be egged out and I think the mounting face has to be sanded a little bit to fit in the jeep booster

09zkrankin · Feb 7, 2016

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Mine is an e350, dont remeber the year but it works great. Running 4 wheel disk on tons and 40's and have no problem locking them down. I dont think i had to egg the holes out but i did have to sand the corners off the flange so that it would fit in the recess on a stock yj booster. It also needed adapters to get it to standard size thread. If you search there is a post, i believe it was on pirate that lists the pn for the master as well as the adapters needed

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mac5005 · Feb 8, 2016

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I did a 69 camaro Mc on my 90yj booster. Had to make a longer pushrod bolt, but was well worth the improvement in Brake feel with the tons. Now it stops like a jeep with one ton brakes. Chevy 60 front, with 14b with discs rear.

69 camaro Mc was cheap and in Stock at my local parts store and was a short but wide all cast iron reservoir.

Also moved ports to driver side giving better access to lines.

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hjpcummins · Feb 10, 2016

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Did a bunch more re search. Ordered both a e350 and d2500 MC. Just haven't got around to swinging by parts store to pick them up.

A buddy had a MC off a mid 90s blazer laying around so picked it up to give it a try. Wouldnt fit. The OD on the MC was to large to got into the booster.

Just thunking ahead before I make a few more trip to the parts store, will most likely the MCs also be to large to mate to booster?

Iv scanned thru numerous threads on brakes, including brake bible.

Is bigger better, like a corvette 1 1/4" MC or is their a simpler math calculator to this chit

RustyC · Feb 10, 2016

Superduty trucks use an 1 3/8" master cylinder piston to fill the huge twin piston calipers. I used an E350 master cylinder (superdtuy brake calipers) and a YJ booster. The E350 helped but was never great.
My wife always complained that she did not feel safe driving due to weak brakes / long pedal travel. I switched to hydro boost and a superduty master cylinder to match the calipers..BOOM. Best brakes on anything I own.

If hydroboost is not an option then a bigger 11/8" plus master cylinder of some kind and a longer pedal may be the answer.

hjpcummins · Feb 12, 2016

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Does anyone have a problem stopping with manual brakes? Not having to stand one the pedal going down steep chit

muddinmetal · Feb 12, 2016

Re:

hjpcummins said:
Does anyone have a problem stopping with manual brakes? Not having to stand one the pedal going down steep chit

Dude, 96 booster and either of the 2 mc you ordered or a Durango one, you'll be fine

joho75287 · Feb 12, 2016

Re:

muddinmetal said:
Dude, 96 booster and either of the 2 mc you ordered or a Durango one, you'll be fine

Booster from a 96 what??
Just curious as I have a soft pedal too. Mine stops good (E350 Master) but I like a more firm pedal...

muddinmetal · Feb 12, 2016

Re:

joho75287 said:
Booster from a 96 what??
Just curious as I have a soft pedal too. Mine stops good (E350 Master) but I like a more firm pedal...

Sorry, the 96 xj booster he already had. 89s had single diaphragms (or the dreaded bendix electric booster) 96s has a dual diaphragm that is much better

joho75287 · Feb 12, 2016

Thanks Muddin!!!

muddinmetal · Feb 12, 2016

joho75287 said:
Thanks Muddin!!!

No problem man, I have used the dual booster and Durango mc on two different jeeps with ford 1ton dual calipers and chevy 3/4 rear calipers with good results. Not out right amazing, but very good

hjpcummins · Feb 14, 2016

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Ended up with 70s ford 1 ton 1 1/4" MC and dual 9" booster, and now I got brakes. Bout MF time. Did good over at chocco but lost all forward gears in the trans.. thanks ppl