Brake upgrade?

[eaglefreek]

I've always thought the brakes on both of the Eagles that I have owned were mediocre at best. Has anyone experimented with other boosters or any other modifications. I've been pondering installing a hydroboost system or possibly seeing if a dual diaphragm booster from a Jeep XJ, TJor ZJ can be made to work.

[HappyPappy]

  If you want a "Hydro-Boost" system for your Eagle, I have a Bendix system I just removed from my Cherokee that you can have, but you will be sorry, can't find anyone to fix them, not even Chrysler dealers, called five of them and they never returned my calls.

  Go to "About.com" and look under "Uninstalling the OEM Anti-Lock Braking System" It's by Steve Ward and there is some info there about which booster you may be able to use, just remember to  get the peddles too. 


  Hope this helps, you can try the bigger wheel cylinders too!  Here is the http link for the site:  http:/.www.naxja.org/html/techarticles/uninstall_OEM_ABS.htm

  Have fun

[eaglefreek]

I didn't know any Cherokees came with hydroboost. I was going to get a booster from an Astro van. Very plentiful in the junkyards and a very common swap on offroad vehicles and hot rods. A lot of the company trucks I drive have hydroboosted brakes and they work quite well.

[rollguy]

The fact that many AMC cars have a GM style power steering pump, makes the Astro Hydroboost system a great choice.  The availability of parts is seemingly endless.

[HappyPappy]

The fact that many AMC cars have a GM style power steering pump, makes the Astro Hydroboost system a great choice.  The availability of parts is seemingly endless.
[/
quote] Yep, called Jeep Bendix 9 Antilock Brakes, completly indipendent of the power steering system, google that and it explains how the failed system was to work, came on the 1989-1991 Jeeps. Would have been a good system if it would have worked.  Glad it's gone.

[eaglefreek]

Yep, called Jeep Bendix 9 Antilock Brakes, completly indipendent of the power steering system, google that and it explains how the failed system was to work, came on the 1989-1991 Jeeps. Would have been a good system if it would have worked.  Glad it's gone.

Did a quick search and it sounds like a bad system. I have no desire to install something that complicated. The Astro or even a Silverado hydroboost would just replace the vacuum booster and some mods to the way it mounts would be made. Factory Eagle brake pedal would be used. I need a new booster now, so I ordered a stock replacement and will use the old one to help mock up a hydroboost or dual diaphragm booster when time allows.

[standup650]

please continue to post on this topic as you find out more. this is a problem i am going to have shortly. what brand replacement did you go with? i have been looking at some of the aftermarket one on summit and wondering what would work and actually be a improvement.

[eaglefreek]

I just ordered one from Napa. Not sure what brand it is. I do plan on doing something with this at some point. Unfortunately, I've been traveling for work a lot with only being home a few days at a time.

[captspillane]

My Scout has the Astro van hydroboost. Its everything it promises and more. I'm amazed at how well it works. There is a substantial difference in rotational inertia when you put 33x12.5R15 tires on a vehicle. The impact to stopping distance is extreme because the tires are so heavy and then that weight further stores substantial potential energy as it spins. After driving the Scout I am hot to trot to put the conversion in my CJ8 and my 401 SX4. 

My Scout used a custom made spacer that the previous owner had made by a friend of his. It eliminated the need to modify the output shaft. Its about 2.5 inches thick and is patterned directly off the bottom of the booster. If you install a hydroboost without that spacer you will need to shorten the input shaft. On mine I can replace the booster with a new off the shelf unit without modifying it. The exact same spacer is needed in a CJ.

The previous owner reported a failure of the booster when he first installed it. He said the source of the problem was later found to be the T from the power steering pump. You need to put the T inline with the brake booster, not the steering gear, because it uses a much larger volume of fluid. The unit was starving for fluid until they changed the route of the hydraulic lines. It was a subtle difference with a big impact.

I believe it will easily fit into my Eagle. The challenge will be to tilt the unit upwards like the stock brake booster. Its necessary to clear the shock tower. A Scout or CJ is very similar but not tilted. I plan on creating a spacer that has two parts. The side profile of one part will be a shallow triangle and the side profile of the other will be a square.

The entire brake booster is also very thin and long because it doesn't need the big round vaccuum booster. I consider this a huge advantage. This means that it will open up enough room to replace the clutch master cylinder without removing the brake system. Indeed I suspect that it will open up enough room to use a CJ intergrated clutch resevoir master cylinder that is currently impossible to install in an Eagle. That's a huge relief. There was a several month time period where rock auto and every other source discontinued the sale of our rare Eagle and Spirit (4cyl only) clutch master cylinders. I searched up and down before finding a place that could get a new unit built special order. I bought 5 then. Now I see rockauto carries them again for about half what I paid for those 5.

[standup650]

first of all what year is your scout? im working on my 66 800a. and can you put some pics of the hydroboost setup and that t?

[captspillane]

Its a Scout II, so its not exactly the same as your 800a. I can ask the previous owner who still owns a '63 and a '77 Scout.

I will post pictures once I'm home. I'll be on my ship doing the whole sailor thing for almost another two weeks. I've only owned the Scouts since December.

Here is my 1980 Turbodiesel Scout Traveler, current daily driver to be replaced by the Kammback soon, and my 1977 Scout Terra.

[eaglefreek]

Here's a pic of one mounted in a Jeep.

[standup650]

captspillane,
thank you for your service! and I'm jealous of your scouts!

eaglefreek,
do you have a pic of the plumbing?

[eaglefreek]

Here's some pics on this site http://www.stu-offroad.com/suspension/vanco/hydroboost-3.htm

[carnuck]

I'm upgrading the brakes themselves first. I scored disc rear brakes from a ZJ to put on the 8.25 rear axle I'm putting in. Then I'm going to try to fit the later ZJ front brakes in. I don't want ABS so I'll be upgrading the booster and master too. (I hear E250 like my '03 works)

Here's a pic of one mounted in a Jeep.

I have that setup for my '84 J10 so I can run the HO 4.0L with stock intake.