My PS lines are running hot, front brakes are hot (not the back) and
the blue cannister behind the Master Cylinder was hot too...

here's what I just finished doing on the truck

Rebuilt the vac pump and put in reman power steering pump.
Filled with syntech ps fluid

Raised the front end and bled PS per Pete Gould's instructions.

Power steering running smooth and fine, seems like I got all the air out, at least the PS reservoir is not frothy and I've driven about 30-45 minutes and PS works great.

PROBLELM...at first pressing brake was a very soft pedal and returned to top in little increments. Then it seemed to act more normal.
THEN the brakes started dragging really bad, soon as I let my foot off the go pedal, truck would really slow down.
I stopped and recheck PS fluid (OK.)
The 2 PS lines by master cylinder were hot! So was the little blue cylinder thingy behind the MC. Brake fluid level unchanged, I have had that master cylinder on and off a bunch over the past month and haven't done a thing to it, looks just fine.
The front wheel brakes were HOT, the rears cool. And definitely was not driving with emerg brake on, and it is working normally.

Got back in, wasn't far from home as this was my maiden voyage after many maintenance repairs..
There was a grabbing and a noise and then the brakes seemed to back off, the pedal was working good again. Still when I got home the PS lines , blue thingy and front brakes still hot.

I drove it 5miles mostly freeway, when I got there that stuff was hot but not as much.It sat for 2 hrs, then I drove home again. Brakes seemed to work fine, no grabbing, but at home the hot parts were HOT again.

Do I need to bleed at the brake cylinders?
Or what? Don't see any leaks in my new VP/PS pump assembly, but haven't driven very far either...

What gives?

 

your PS/hydroboost system is going over relief constantly, this is what is causing the overheat.

Some sort of restriction in the system is what causes this, as the fluid is forced past the restriction, it heats up.

I cannot tell you at this point, what the actual problem is, because my brain has ceased to function for the day, but that is what your symptoms are describing to me.

 

Hmmm,
I'll recheck my PS fluid, I tried to make sure it wasn't overfilled, but I'll check again...I know it was clean in there...I thought everything was clean, I had removed both pressure lines from the steering box and of course all the ps pump lines...
could the oil line to the vac pump have a problem? Maybe I didn't keep things as clean as I thought? I sure don't want to break what I just tried to fix.

 

Obviously the front calipers are not releasing. I can think of three things that would cause that. 1. Bad caliper....not likely both would fail at one time. 2. Restriction in line or flex hose....again not likely both sides at once. 3. That only leaves the master cylinder. Have you flushed the brake fluid? If so, did you push the brake pedal to the floor? That could damage the MC. If not, give it a shot. Quick and inexpensive. Put a 2X4 under the pedal to restrict it's travel.

 

I drove into town and bought a paper. When I got home I checked the lines to the booster for heat. The outside (pressure) lines were warm, but not too hot to keep my hands on them. The center (return line to the reservoir) line was cool, as was the blue accumulator. I conclude there are more possiblities, which are a bad booster/accumulator or a clogged port or pressure hose. My FSM gives this procedure to check the accumulator:
With the engine off depress the brake pedal several times to discharge the accumulator. Depress the pedal using 40 lbs of force and start the engine. The brake pedal should fall then push back against your foot. To check for leakdown,(1) with the engine running apply the brakes and turn the steering wheel lock to lock. This ensures the accumulator is charged. Turn off the engine and let the vehicle sit for one hour. After an hour there should be at least two power assisted brake applications with the engine off. If the system does not retain a charge the booster must be replaced. (2) With the engine off discharge the accumulator. Grasp the accumulator and see if it wobbles or turns. If it does the accumulator has lost it's charge and the booster must be replaced. (side note from my experience. If the PS fluid pukes out with the engine off it is likely the accumulator/booster assy has failed).
There are three things that will cause the brakes to self apply in the booster system. 1. Dump valve faulty...replace booster 2. Contamination in hydraulic system.. flush hyd system (I think they are talking brake fluid flush here, I would do both) and replace booster 3. restriction in booster hose....replace hose.

There are other faults/causes for booster system diagnosis, but I think I listed your main complaints.


BTW "There was a grabbing and a noise and then the brakes seemed to back off, the pedal was working good again" was probably your front discs were fading and you were then using the rear brakes to stop.

HTH

If you are relying on a cheap imitation repair manual I suggest you spend the $$ for a factory one. It will pay for itself quickly.

 

On hot PS lines. They gonna get warm. Generating 2000 psi or so as brakes and steering do work.
On solid pedal (?) and hot brakes. When conditin exist (hot brakes) raise a wheel enough to turn by hand. Is it tight? Calipers may be occasionally hanging. Common enough problem easy to fix with reman calipers
on PS fluid. Replace ps fluid seems very needed especially during cold weather. Just fixed wife's car with similar issue.
on restriction in line. PS will sort of grind if pressure high from restriction. Will sound like at full turn and squaling. Hoses will also be taut and not go relative limp when not breaking or turning.

 

Games:With the engine off depress the brake pedal several times to discharge the accumulator. Depress the pedal using 40 lbs of force and start the engine. The brake pedal should fall then push back against your foot.
When I first did this yesterday, pedal was firm and didn't fall.
BUT after the truck sat for several hours yesterday, I got back in and took a drive. Now the pedal falls while driving, then comes up again. Pedal does feel very firm when applied.
Brake pedal rests a little lower than clutch, but I think its always done this.

Drove to work today, truck acted "normally" like you both mentioned above: PS lines and front brakes moderately warm, actuator not warm. PS works great, brake pedal as above. Brakes not sticking.
Hopefully the PS/hydroboost was just adjusting and has sorted itself out.

Thanks for the input, and I'm glad things seem resolved, I'd like to go trouble free for a while.

I do have a new symptom I'm thinking related to the vac pump, will post in new thread.
thanks again for the input

T

 

If you look at the souped-up gearboxes and pumps, some of the larger ones need ps fluid coolers.. so Id imagine getting warm is pretty normal.
The brakes probably are dragging. Look at the rotors for bluing if its excessive.
Theyre cheap to replace. Put some grease on the fittings for the next poor soul though.. those bleeders and whatnot are a PITA to get off when they corrode.

 

Thanks Kawi600, Ill check 'em and see..

I was looking on the back side of my front wheels yesterday, and I noticed the line that goes in, just below the bleeder valve, was very rusty on both sides..I wondered if that every breaks or leaks...I didn't think it looked like a replaceable part or removable part...
Is that what you're talking about?

On my MINI I put steel braided brake hoses and bushings...if I remember, the brake lines under the Dodge aren't steel braided...
does upgrading them yield any increase in performance?
definitely the time to replace them if I'm getting in there...