Diesel Place banner

1 - 11 of 11 Posts

·
Registered
Joined
·
72 Posts
Discussion Starter #1
I just had to replace the hydroboost a couple weeks ago and thought I'd post some photos to help anyone else out that's never done this.

The hydroboost uses the power steering system to assist the brakes. When mine went bad I first noticed a whine that I thought was the turbo. It turned out this was the power steering pump and it was almost empty of fluid. Everything had leaked through a broken seal inside the hydroboost. After the whine noise started braking and steering were difficult.


Pic of the hydroboost. It's the unit bolted to the master cylinder and the firewall. Mine leaked all the fluid out the side connected to the master cylinder. I've heard others leak into the cab.




To remove it
1. unbolt it from the master cylinder, carefully pull the master cylinder out of the way but leave it connected.

2. disconnect the brake light switch from the brake pedal. It will pop off.

3. disconnect the brake pedal from the hydroboost by removing a small clip that hold it on. Different years have different style clips. This is what mine looked like.




Use a set of snap ring pliers or a screwdriver to open the clip. It's in a tight spot and difficult to get at.

4. Loosen the 4 bolts holding the hydroboost to the firewall and then disconnect the hydroboost from the brake pedal.

5. Finish removing the 4 bolts. A 3/8s drill adapter, 12" extension, and deep sockets make this easier. They are also in a tight spot with not much room to work.

6. Remove the old hydroboost



Next will be the install
 

·
Registered
Joined
·
72 Posts
Discussion Starter #2 (Edited)
Installation part 1

1. Before ordering a reman unit check the JD code in the glove box. It should JD5, 6, 7 or 8. Make sure the new part matches this code.

2. Check the power steering lines for leaks and replace if needed. They can be replaced without removing the pump and there are 5 lines total.
a. High pressure line from pump to booster
b. High pressure line from booster to steering gear
c. Low pressure return from booster to pump
d. Low pressure from cooler to pump
e. Low pressure from gear to power steering cooler (this cannot be ordered with out getting a new cooler or cutting the old line off the fittings and using new PS hose and clamps)

The power steering cooler is on the right of the oil cooler in this pic


Mine were leaking at the high pressure fittings so I replaced them



3. The reman unit will require you to reuse 3 parts from your old unit. Be careful not to bend when removing. This is what they look like. I used needle nose pliers to remove and a large socket to press into place on the new unit.





Installed

 

·
Registered
Joined
·
72 Posts
Discussion Starter #3
Installation part 2

1. Put the new unit in but do not tighten the bolts yet. Slant it towards the drivers side.

2. Reconnect the brake pedal to booster. Do not force it. If you have it unbolted and angled towards the driver's side it should fit back on.

3. Straighten the booster and reconnect the brake pedal switch

4. Put the small clip back on the brake pedal

5. Tighten the 4 bolts to the firewall

6. reconnect the master cylinder

7. reconnect the power steering lines to the booster but leave off the return for now.

8. check that the steering lines aren't rubbing anything


Flushing the power steering

1. connect a 4 foot piece of clear tubing to the hydroboost return and run the other end of the tube into a bucket for waste oil.

2. fill the power steering pump and start the truck. Turn the wheel left and right until the pump gets low. Then stop the truck add more fluid and repeat until clean fluid is coming out of the hydroboost return into the waste bucket. I think I used about 4 quarts.

3. Reconnect the hydroboost return line. Start the truck check for leaks and add more fluid if needed.


Done
 

·
Registered
Joined
·
5,548 Posts
I just swapped the leaky unit on my 96 and will add a few tips. Hopefully besides fixing the leaks it will also help my problem of loosing both power brakes and steering while going down a cloverleaf ramp where you have to steer and brake at the same time with the engine basically at idle. My hope is that the leaks in the booster were bleeding off too much pressure.

There is a JD5/JD6 unit and a JD7 unit. Not sure what the difference is but they are listed as different part numbers so check your sticker so you get the right one.

One line is 18mm and a 5/8 fits the other. Had to use a crow foot on one. not a ton of room to work around the lines.

Like everything in the cab firewall the insulation seems to just be in the way. I would estimate the job would take 3-4 times longer with the insulation in place. Cutting it out takes 5 seconds and gives you a lot more room to work.

Run a thread chaser and or wire wheel over the 4 studs that mount to the firewall, the remans tend to have paint on them and sometimes dings in the threads. Access to those nuts sucks so you want things to go as smooth as possible. I could only get my 3/8 air ratchet on one nut, the others were regular ratchet and 1-3 clicks per swing which takes forever with an inch or so of threads. Its a 15mm and has to be a deep due to the length of the studs.

To get that star thing out that holds the pushrod in I was able to just find the right angle with one point in that drain groove in the casting. Was able to pop it out and in with bare fingers.

New orings for the pressure lines came with my a1 cardone unit. check to see that yours comes with them too, if not get em. often times the originals are crushed and will leak if you don't replace em.

When you are wrestling the unit back through the firewall be sure the pushrod ends up on the correct side of the brake pedal. For some reason this took me several attempts. It would start on the correct side but somehow end up on the wrong side and you can't get it on the correct side without almost fully pulling the unit out again. check to be sure all the wires and hoses are where they should be and that you don't have anything pinched.

If yours is still factory the return line hose has a crimped hose clamp. You will need a regular hose clamp to put things back together.

My replacement unit seems to have an extra dodad line thing on the return port. Not sure what it does. Old one didn't have one. Makes clearance for a flare wrench tight on one of the lines but otherwise does not seem to make any difference.
 
  • Like
Reactions: vstech

·
Registered
Joined
·
3,999 Posts
  • Like
Reactions: quadstar87

·
Registered
Joined
·
820 Posts
Very cool thanks for the thread and pixs. I like to post how to threads with pictures. I think every post should have a picture to go with it lol even if unrelated share a chick in a bikini
 

·
Registered
Joined
·
2,532 Posts
Thank you for writing this post!

Now I have an inkling what that strange WHINE noise is under my hood. And my brake light comes and goes sometimes :wtf:

I already did this once. Aparently the reman doesn't last nearly as long as the original.
 

·
Registered
Joined
·
5,548 Posts
I didn't start it, just found it during my research before starting the project and figured I would add to it since he did a nice job to start with. Looks like the guy that started it has not been around since Aug.
 
  • Like
Reactions: Diaric

·
R.I.P. Sam
Joined
·
32,077 Posts

·
Registered
Joined
·
1,282 Posts
My photo article is at this link:



I think every post should have a picture to go with it lol even if unrelated share a chick in a bikini
:rolleyes: :think: So where's your bikini chick? :shake: :wtf: :confuzeld
 
1 - 11 of 11 Posts
Top