leaking power steering fluid by master brake cylider

[duramaxdude]

Im not sure what to do about this problem. When I step on the brake my truck leaks PS fluid out the bottom of the master brake cylinder. Is it a seal or do I have to replace the whole unit. Just wondering if this happened to anyone

Also why is there power steering fluid in the brake cylinder. Im not sure how that works.

thanks

 

[NVW]

The PS and brakes are combined, I can't help with the leak. Haven't been there done that yet.

 

[Jess_sr]

Power assist for the brakes use a Hydro boost set up powered by the power steering pump.

Sounds like you need to replace your Hydro boost Unit.

 

[WarWagon]

You can rebuild the Hydrobooster, but, good luck getting parts. You need to know if you are 8 lug etc or get the (JD7) number out of the glove box.

Your leak means the hydrobooster has blown a seal. As diesels do not have a intake vacuum from a throttle blade you would need a big vac pump for a vacuum booster. Dodge does this, we use the power steering pump instead. So we have a hydro booster. Be prepared to spend $300.00 for the 1 ton system. 6 lug may be less.

 

[Desert]

Your power piston seal is leaking. There is a drain hole between the hydraulic booster and the master cylinder. If you check where the pedal rod enters the housing the input rod seals are most likely also leaking. MBM makes a repair kit $40 - $65 plus freight. It is worthless if you have a staked pedal rod as you must saw it in half and no one sells the replacement pedal rod, that I could find. See the attached instructions.
View attachment Kit 50 Instructions.pdf
Know your vehicle's RPO code before trying to buy a replacement from the parts stores.
JD6 : BRAKE, HYD POWER, DISC/DRUM, 7200 LBS
JD7 : BRAKE, HYD POWER, DISC/DRUM, 8400 LBS
NAPA $163.00, The wrong booster was in the box.
Auto zone $200.00, two days. TOO LONG A WAIT.
O'Rilley $210.00 in stock. I had to go back and get my output rod assembly from the core. We swapped the new part and core and I missed the paper that said to reuse the output rod. Limited Lifetime Warranty. I keep my vehicles a long time and it pays back in parts costs.
If the new part does not have the exact same build as your old unit I would not buy it!
Removal can be frustrating, the retainer clip for the brake switch and pedal rod is a PITA. I finally just pried it off and straightened it back out. This is located directly above the steering shaft.
Repair
1. Discharge the accumulator. Engine off. Depress the brake pedal 5 - 10 times.
2. Unbolt the master cylinder from hydraulic booster and bend lines to locate out of way.
3. Disconnect input rod from brake pedal and remove brake switch from input rod.
4. Disconnect hoses and plug hoses and ports.
5. Remove 4 ea nuts from mounting bolts.
6. Remove unit.
7. Reassemble in reverse order
8. Bleed air from system. Fill reservoir and keep full. Start engine. Rotate steering wheel stop to stop while depressing brake pedal repeatedly.

I thought I could save some money with the seal kit but I should have just bought a reman from the start.

 

[duramaxdude]

Your power piston seal is leaking. There is a drain hole between the hydraulic booster and the master cylinder. If you check where the pedal rod enters the housing the input rod seals are most likely also leaking. MBM makes a repair kit $40 - $65 plus freight. It is worthless if you have a staked pedal rod as you must saw it in half and no one sells the replacement pedal rod, that I could find. See the attached instructions.
View attachment 20786
Know your vehicle's RPO code before trying to buy a replacement from the parts stores.
JD6 : BRAKE, HYD POWER, DISC/DRUM, 7200 LBS
JD7 : BRAKE, HYD POWER, DISC/DRUM, 8400 LBS
NAPA $163.00, The wrong booster was in the box.
Auto zone $200.00, two days. TOO LONG A WAIT.
O'Rilley $210.00 in stock. I had to go back and get my output rod assembly from the core. We swapped the new part and core and I missed the paper that said to reuse the output rod. Limited Lifetime Warranty. I keep my vehicles a long time and it pays back in parts costs.
If the new part does not have the exact same build as your old unit I would not buy it!
Removal can be frustrating, the retainer clip for the brake switch and pedal rod is a PITA. I finally just pried it off and straightened it back out. This is located directly above the steering shaft.
Repair
1. Discharge the accumulator. Engine off. Depress the brake pedal 5 - 10 times.
2. Unbolt the master cylinder from hydraulic booster and bend lines to locate out of way.
3. Disconnect input rod from brake pedal and remove brake switch from input rod.
4. Disconnect hoses and plug hoses and ports.
5. Remove 4 ea nuts from mounting bolts.
6. Remove unit.
7. Reassemble in reverse order
8. Bleed air from system. Fill reservoir and keep full. Start engine. Rotate steering wheel stop to stop while depressing brake pedal repeatedly.

I thought I could save some money with the seal kit but I should have just bought a reman from the start.

Thanks for the info. I will buy a brand new unit and put it on. I was trying to get a look at that picture but its not working. Could you try to post it again please.

also how much of a PITA are these things to bleed? I've never had to bleed brakes so I dont know what im in for.

 

[Desert]

Thanks for the info. I will buy a brand new unit and put it on. I was trying to get a look at that picture but its not working. Could you try to post it again please.

also how much of a PITA are these things to bleed? I've never had to bleed brakes so I dont know what im in for.

The image is a PDF link. Click on the image and the file should download.

Bleeding the hydraulic booster is easy. Fill the power steering pump reservoir and keep it full. Start the engine. Rotate the steering wheel from stop to stop while depressing the brake pedal repeatedly.

A "new" unit will run you $483.00 at Rock Auto without the discount. A remanufactured unit is $150.00. All of the other parts stores sell remanufactured units.

 

[Jess_sr]

Thanks for the info. I will buy a brand new unit and put it on. I was trying to get a look at that picture but its not working. Could you try to post it again please.

also how much of a PITA are these things to bleed? I've never had to bleed brakes so I dont know what im in for.

Just unbolt the master cly and move it aside. No need to open the brake fluid system just to replace the booster

 

[duramaxdude]

Just unbolt the master cly and move it aside. No need to open the brake fluid system just to replace the booster

Thanks for the advice. I'll diffently think about doing that.

 

[gearedandready]

Thank you for this thread.

I had to replace my booster this weekend.

I want to add that the reman unit I purchased did not come with the Rod, Spring, and Retainer clip inside the brake booster, at the end of the booster down the hole where the piston is.

Inside my existing brake booster I used a pair of needle nosed pliers to work the retainer spring out. Careful not to bend or brake the retainer spring. First the spring will come out, then the coil spring under it, then the actuator rod (which has a plastic ring on the bottom to orient it in the piston in the brake booster). Note how the pieces come out, put back in the new/reman unit in the same order.

1. Actuator Rod (with plastic ring towards back of brake booster)
2. Coil Spring
3. Retainer spring (with bent edges facing outward, or towards where the master cylinder would be)

Check the retainer spring to see if it needs to be bent back into shape. Mine was a little bent after removing it from the original brake booster.

Not a bad job, took about an hour and a half. Used a couple of extensions, a universal, and a 15mm deep socket to get nuts under dash out. The nut in the lower right corner when facing forward under the dash is difficult, I could not get a socket on it, had to go small turns with a standard wrench, a gear wrench with a universal bend on it would work wonders.

Thanks for this post was really helpful.

 

[Suburbank2500]

GMpartsonline.net have it for $376.57

 

[duramaxdude]

I finally replaced mine a year ago but now i sold the truck I miss it already it got me through highschool and i barley did anything to it but drive it like i stole it. I had alot of fun with that truck:hihi: it still runs like a top to this day..

Ive spent more money on my stupid LBZ in the four months ive owned it with brake problems and i actually take care of it lol

 

[chefmike]

I really need to do this... Just keep filling my ps fluid. I just cannot visualize how to get the brake pedal end off. It is buried up in there. I can barely touch it. I am still to scared to rip into it with sheer hope I can get it clipped back on.

Argh.

 

[1995yukon65]

It's not hard, I have large hands so I use a long thin flat head screw driver to pop the clip up enough to push it off with my hand. The hardest part is getting the one nut off that is right next to the column.

 

[someotherguy]

There are two designs of clip that hold the rod onto the brake pedal. Neither are a hassle once you know the trick.

Up to 1994-maybe 1995, it's a rectangular clip you can simply slip a small flat screwdriver into the top edge and release it from the stud on the rod.

1996-up (and maybe 1995 too) it's a round clip that at first seems impossible to remove. Take a step back and a deep breath. Then spin it around on the stud until you see the split in it, and you'll also see two small half-circle holes on either side of the split. Use snap ring pliers to gently pry it apart there at the split a tiny little bit and you can then easily slide it off the stud.

No destruction necessary.

Richard

 

[chefmike]

Thanks guys... I am going to order the booster and tear into it. I got a booster once from napa, but it was not the same as mine, so I returned it. I will try again. Maybe rockauto or oreilly's.

Thanks for the tips. I will take another look at it.

 

[chefmike]

It looks like I have the rectangular type and I now see where I can slide in a screwdriver to release the post i guess. Now i just need to find the right hydroboost unit.

 

[btfarm]

There ya go Mike. A little confidence booster from the TTS brotherhood and you're all set as soon as you get the parts. Might check Rockauto and if they have it don't forget to use the latest discount code from the deal finder thread.

 

[Pruittx2]

and take pics, for us too. The kind of pic's that help remove the doubt's you had, that makes it easier for the next guy to jump right in and do it!

 

[chefmike]

All righty folks. The job is done. I took some pictures in hopes of helping others. Hard? Not really (once you have done it!). I am not a great mechanic, I get frustrated and curse at the burb. But I am generally pretty conservative and have alot of stamina to keep trying. Great attributes for owning a 6.5!

I followed the steps listed in one of the above posts, which are also the same as the steps on the sheet in the box. I was actually impressed. I got a cardone remanufactured from Oreillys, which was the same price as rockauto. The only difference between the "new" one and my leaky unit was a hose between a port on mine and the return valve. This did not exist on the "new" one, but I decided to go for it.

I removed the master cylinder and it easily moved out of the way.
I then removed the retaining clip on the input rod end. Look at the top of the brake pedal to the passenger side of the steering column. I have a 1995, so it is square. And it was the hardest part of the whole job. I tried to pry. I tried to be nice. I finally just ripped that little piece of crap off because I was tired of cutting my knuckle in the same place over and over getting my hand up in there to hold the clip while I jimmied at it with a screw driver. If this thing was in the open, you could have it off in 15 seconds. Or maybe I am just this stupid.

This is the clip. Simple design, really. It has a hook that grabs the groove on the end of the pin. Maybe the two holes on the back are for a tool that magically removes it. I would have paid you about anything for that tool:

Then I pulled the hoses and removed the 4 mounting bolts. I used 15mm deep socket AND regular socket on each, with a universal and a 12" extension. I started them all with a 15mm box wrench, then placed the deep socket on. I used my cordless drill to drive the socket, which worked great. I switched to the regular 15mm socket to finish each. I could get to each bolt this way and was done quickly. The socket adaptor for my drill was the best $4 I ever spent!

There were instructions in the box about keeping the retainer spring and rod that is mentioned in a post above. I followed our brother's instructions to use a pair of needle nose pliers and remove the 3 parts:

The socket for injectors (1and 1/16?) works perfect as a quick press to place the retainer plate into the new hydroboost.

It all went back in fairly easily. The freaking retaining clip was again the hardest part. I will likely get a new one or replace it with another solution. DUMBEST DESIGN. I think I have heard people say it was considered by chevy to be a single use part.

So there you go. If I can do it, you can. It was a 3 beer job. I hope this helps someone in the same way so many on here have helped me.

Forgive the links... I could not get the pictures to appear. Maybe I can think about it tomorrow. No more desire tonight!