The brakes breaks !

[wildcatjason]

Does it have 3 ports on the back of the pump? One pressure and two returns? Dodge had a vacuum brake some years and hydraulic brakes others. I don't know which years but I've seen both. You should have 2 return ports on the back that thing.

 

[clkelley]

Did you flush the PS fluid? I know I said this before, and yes I know that some people don't have faith in it, but if you want the pedal back, flush the power steering fluid. Spongy pedal after everything else has been considered in the regular braking system is usually diagnosed in these steps, at least around here. Does the fluid need flushed? Flush it. If that doesn't fix it, like stated above, is the PS fluid foamy? If it is then the pump is either on it's way out or gone already. That's pretty much it. If the hydroboost unit goes out completely then more than likely the pedal will be so hard it will will barely move when you try to push it.

 

[TexasOutlaw87Cummins]

Did you flush the PS fluid? I know I said this before, and yes I know that some people don't have faith in it, but if you want the pedal back, flush the power steering fluid. Spongy pedal after everything else has been considered in the regular braking system is usually diagnosed in these steps, at least around here. Does the fluid need flushed? Flush it. If that doesn't fix it, like stated above, is the PS fluid foamy? If it is then the pump is either on it's way out or gone already. That's pretty much it. If the hydroboost unit goes out completely then more than likely the pedal will be so hard it will will barely move when you try to push it.

Yea I flushed the system it's all new fluid . The cummins engine that I have in the truck is a 1993 VE injection pump engine . So it's used vacume booster in the original dodge truck . There's only one inlet for return so basically it's layed out like this . Back of power steering pump to hydro booster . Hydro booster to steering box . Both returns from hydro and steering are piped toghter to go to a cooler I have set up up front ( 86 454 engine oil cooler) so then after the cooler it goes back to the pump in one line . So maby the 2 returns are fighting each other ? I'm not sure . This is my first cummins swap and really the first time I've messed with these trucks . I had a old 83 when I was 16 that had a 6.2 diesel in it . But that's where I'm at . Thanks for all the info ill take pics of how I haven't routed later today .

 

[skysurfer]

Did you bleed the p/s system by raising the front wheels and turning the steering wheel lock to lock? I've read 20-30 rotations will do the trick but for mine it was well over 100.

 

[TexasOutlaw87Cummins]

Before I connected the steering linkage I did I turned it a few times .. Maby I should tri it again

 

[chengny]

You must be registered for see images attach

As per Mr. skysurfer's advice, more lock-to-lock strokes are often required. See steps 4,5 & 6 above. The minimum GM suggests is 40 - and that is with a basic P/S system.

When additional lines and components are involved (like the hydroboost actuator in your situation) it takes longer to bleed the air out. There is no actual written procedure for bleeding a P/S with an associated hydroboost system but what I do is like this:

While the front end is up and the engine is running, fill the P/S reservoir to the very top.
Then get in the cab and stroke the steering to the stop a few times.
Get out and again fill the reservoir to the top if needed.
Get back in and resume cycling the steering. This time, while rotating the steering wheel, pump the brakes.
Use long deep strokes on the brake pedal. Pump the brakes maybe 20 times and then stop. Keep cycling the steering system stop to stop. After a minute or so do the brake pump again.

Get out and check that the P/S res is still topped up. If not, fill it and repeat.

This is much easier and more effective if you have a helper. He can monitor the reservoir for bubbles and continuously add fluid as required.

 

[skysurfer]

My understanding, and chengny's attachment would agree, is that the engine remain off while this is being done.

 

[wildcatjason]

2-3 times of rotation won't be enough to push the air out of your PS system. X3 on doing it with engine off. I don't know if the hydroboost system is going to get enough fluid return with only one port. Mine had 2 returns and worked great.

 

[chengny]

The hydroboost actuator is located about 2 feet above the highest point in the hydraulic portion of the steering system. That is an important distinction.

In a standard (i.e without a cooler or hydroboost brakes) steering system, the P/S fluid reservoir is the high point. Stroking the steering manually from stop to stop will effectively purge the air from the steering gear and any associated lines/hoses as long as they are below the pump. Any air entrained in the hydraulic fluid moves along with it, eventually migrating to the highest point - the reservoir. Once there it bubbles through the fluid and is released to atmosphere.

However, if there are extra components (and their connecting hoses/lines) that are connected to the P/S hydraulic system, normal purging methods are not as effective. And, if they are located a signifcant distance above the reservoir (as in the case of a hydrobooster) the purge process becomes more involved.


Without the engine (and by association the P/S pump) running, fluid flow is restricted to only the parts of the system at or below the level of the pump.

In order to over come the static head, and move the volume of fluid that is located above the steering gear, the pump must be running. I only raise the front end to expedite the process - it can be done with the tires on the ground.

Here are a couple of published hydroboost bleeding procedures:


Service:
The hydro-boost in not serviceable in the field. If the unit is not functioning properly, it must bereplaced. The replacement process is straight forward, but bleeding can sometimes be tricky. There are a choice of techniques in this area. Hydro-boost brake systems are supposed to be self-bleeding, but this does not always prove to be true.

Bleed Technique:

Replace any hydraulic line showing external damage. Install new seals for all disconnectedfittings (as required) and install an in-line power steering filter. Tighten all hose fittings to OEspecifications.

2. Flush the entire power steering system using the vehicle manufacturer's recommended fluid.Fill pump reservoir to the proper level.

3. Disable engine to allow cranking without starting. Block wheels, put transmission in neutral or park and set parking brake, then crank engine 5 to 10 seconds (avoid overheating starter motor).

4. Refill pump reservoir as necessary. Repeat step 3 until level is correct.

5. Enable the engine to allow starting. Start engine and let idle. Slowly turn steering wheel fromlock-to-lock a number of times.

6. Turn engine off and inspect fluid level and condition. Add or remove fluid as necessary. If fluidis foaming, wait one hour then recheck level. Repeat step 5 and 6 until fluid level is correctand shows no sign of air problem.


HYDRO-BOOST SYSTEM BLEEDING



The system should be bled whenever the booster is removed and installed.

1.Fill the power steering pump until the fluid level is at the base of the pump reservoir neck. Disconnect the battery lead from the distributor.


Remove the electrical lead to the fuel solenoid terminal on the injection pump before cranking the engine.

2.Jack up the front of the car, turn the wheels all the way to the left, and crank the engine for a few seconds.

3.Check steering pump fluid level. If necessary, add fluid to the ADD mark on the dipstick.

4.Lower the car, connect the battery lead, and start the engine. Check fluid level and add fluid to the Add mark if necessary. With the engine running, turn the wheels from side to side to bleed air from the system. Make sure that the fluid level stays above the internal pump casting.

5.The Hydro-Boost system should now be fully bled. If the fluid is foaming after bleeding, stop the engine, let the system set for one hour, then repeat the second part of Step 4.


The preceding procedures should be effective in removing excess air from the system, however sometimes air may still remain trapped. When this happens the booster may make a gulping noise when the brake is applied. Lightly pumping the brake pedal with the engine running should cause this noise to disappear. After the noise stops, check the pump fluid level and add as necessary.

 

[clkelley]

chengny, those are great write ups. you should put all that into one thread covering the ps system bleeding, etc.

 

[TexasOutlaw87Cummins]

Yea thank you so much !! I just been busy with work ! Ill get it figured out this week got sure