Hydro Boost Groaning.

[Darkbloodmon]

03 HO 2500 214.9K MI:

Noticed a groan when I was braking and got home and heard it coming from the hydro, it was flooding and frothing up my power steering res.

So I picked up a used hydro with 109K on it from an 06 2500 swapped it in bled it (lock to lock truck on, pump brake truck off x 3 add fluid as needed. For reference if it makes a difference my original hydro had a blue solenoid, the used one I swapped in had a silver one, i've heard different color for different pressure but since it was another dodge I assumed it was good and sent it since everything lined up.

Still had a bit of a groan but i've since made a 50/50 cocktail of ATF 4+ and lucas stop slip since its ATF (pulled out the fluid in the res and dropped the drink in I know it's not a full bleed). It helped some but still pushing some fluid out the reservoir. Have not road tested yet. ( the swap and cocktail was all done this afternoon). No leaks on my hoses of hydro or gear box all fluid is ******* out the P.S. Res.

Since i've got the old one off I plan on rebuilding it incase the one from the 06 is bad as well. Though I wanted to know if im missing anything diagnosis wise before i start chucking a new power steering system on it. My symptoms before I dropped the cocktail in were groaning on lock to lock travel and getting on the brake all pushing fluid out the reservoir.

I apologize if this has been covered already in this thread, im having a hard time searching it.


P.S. for anyone else doing this repair it's "required" that you swap the brake light switch. Though my local Cummins hoarder let me in on a trick to keep the OEM one since she's tried aftermarket auto parts store ones that fail, pin the pedal so that it doesn't drop with a bungee cord or zip ties to keep it at the same level, pull of the hydro arm, get out get in and Bob is your uncle.

Thank you in advance.

 

[MGreer]

I've read about a screen on the pressure line of the power steering pump getting clogged up. Sounds like it might be worth looking into.

 

[Darkbloodmon]

I've read about a screen on the pressure line of the power steering pump getting clogged up. Sounds like it might be worth looking into.

Alrighty I've been mulling this one over for a while now as far as the mechanical logic to my problem.

Correct me if im wrong.

PS Hydro system:

PS pump sends fluid through a high line to the hydro (hydro is pressurized with a low line draining excess back to pump)

Hydro sends fluid still pressurized through a high line to gear box (gearbox sends fluid through a low line through cooler which sends low back to PS pump. Both low sides back to the pump are fed by a T from the cooler and the hydro.

According to you the high line coming off the pump is in question because of the inline filter mesh.

So if I have a blockage what happens (pressure rises, some fluid still gets through)
So I have a lower flow ( of fluid ) throughout the system due to the blockage which is building up pressure even as fluid is being returned back from the whole system
The fluid that is being pressurized in the reservoir against the blockage with the returns still flowing back are causing it to overflow at the cap.

Thus assuming my truck: Giovanna Basia de Sirou is operating fine on the hydro i just installed and the box and pump that are on her, I need to clear out the high line blockage or replace it entirely.

 

[Ozymandias]

Does the reservoir oil foam over or is it still fluid?

 

[Darkbloodmon]

Does the reservoir oil foam over or is it still fluid?

I just notice fluid coming out of the top after some time, I didn't open the system while the truck was running. The High line from the pump to the hydro feels really aerated compared to the High line from the hydro to the box. What does it signify?

 

[Ozymandias]

I wild guess you have an airleak somewhere, or there is still air in it from the repair.
Mine took some Time to get all the air burped after i changed the steering gear. It wasn't done in 5 minutes, mir like 5 hours of starting and stopping the engine, refill the reservoir, wait fir the air to settle, turning the steering wheel and so on..

 

[Darkbloodmon]

I wild guess you have an airleak somewhere, or there is still air in it from the repair.
Mine took some Time to get all the air burped after i changed the steering gear. It wasn't done in 5 minutes, mir like 5 hours of starting and stopping the engine, refill the reservoir, wait fir the air to settle, turning the steering wheel and so on..

So were talking about a pressurized fluid system here and ideally we are moving nothing but fluid.

I have fluid being pushed out the top of the reservoir because of the excess pressure being built inside of it from an assumed blockage.

Do I have an air leak? Yes out the top of my reservoir. if I had a leak on the hi side of the system it would be pushing fluid out.

Could there still be air in the system? Yes. The excess pressure from the assumed blockage on the high line from the pump to the hydro is definitely aerating the fluid and there is a volume loss of fluid moving through it so it could have space for air.

I have no additional leaks on my hydro system besides the Power steering reservoir cap i've sprayed the fittings with soap water.

Here is my game plan going forward. I'm going to replace the old high line from the pump to the hydro which will require me to rebleed the system again. Lock to lock truck on and pumping the brakes truck off. Im then going to cut open the old high line and look for my blockage. I'll share my results here as well as the other forums i've visited since I could not find any past articles with objective information on this particular issue. Lets see what happens.

 

[seafish]

FYI--it was a fairly common occurrence on 3rd gen trucks for the plastic liner INSIDE of the hydroboost line to slip out of place and work ira way into the brake booster and restrict flow. IIRC, the slippage was sometimes accompanied by a groaning noise. The easiest solution was to disconnect the line and remove the complete liner with a pair of needle nose pliers then reconnect the line. If the noise and aeration disappear, then you have found your problem. Some people simply kept running WITHOUT the liner, but I'd imagine it would be a good idea for the long term to eventually replace the hose with a new one.

 

[Darkbloodmon]

FYI--it was a fairly common occurrence on 3rd gen trucks for the plastic liner INSIDE of the hydroboost line to slip out of place and work ira way into the brake booster and restrict flow. IIRC, the slippage was sometimes accompanied by a groaning noise. The easiest solution was to disconnect the line and remove the complete liner with a pair of needle nose pliers then reconnect the line. If the noise and aeration disappear, then you have found your problem. Some people simply kept running WITHOUT the liner, but I'd imagine it would be a good idea for the long term to eventually replace the hose with a new one.

When you say inside of the Hydro high line are you talking about the pump to the hydro, or the connector hard line finally to the hydro? How easy is it to access and from which end?

 

[seafish]

When you say inside of the Hydro high line are you talking about the pump to the hydro, or the connector hard line finally to the hydro? How easy is it to access and from which end?

IIRC it was pump to hydro on the hydro end...all you need is a wrench.The new part # is updated and does NOT have the liner.

There are several older threads that you might want to read.

https://www.turbodieselregister.com/threads/hydroboost-line-p-n.258088/
https://www.turbodieselregister.com/threads/hydro-boost-noise.234217/


All that said, I am not saying that is defiantly yours problem, but that you should look into it as a possibility.

 

[Darkbloodmon]

IIRC it was pump to hydro on the hydro end...all you need is a wrench.The new part # is updated and does NOT have the liner.

There are several older threads that you might want to read.

https://www.turbodieselregister.com/threads/hydroboost-line-p-n.258088/
https://www.turbodieselregister.com/threads/hydro-boost-noise.234217/


All that said, I am not saying that is definitely yours problem, but that you should look into it as a possibility.

Thank you for the links, I figured out how to search through the archives. I will still post my results and findings here.

 

[Darkbloodmon]

Follow up on my fix:

My solution (TLDR High pressure line swap, and patient vacuum bleeding, don't over fill the reservoir, it'll overflow making you think you have a leak, After cutting open the lines, the high line with the middle clamp (pump to hydro) has a liner with small orifices, the non middle clamped line (hydro to box) is a wide open non lined high pressure line (full send on fluid pressure) .

swapping the high pressure lines. My hypothesis on there being a high line (power steering to hydro) blockage in the liner was correct. There is a clamp on the high line right about 2/3s from the top end to the hydro at that clamp there are two orifices with very small holes and a space between them for what i assume is for building pressure. The pump is pushing fluid through this joint with a small opening which is pressurizing the fluid, if in that orifice you have a blockage it could lead to too much pressure building in the system, meaning what fluid that does get through is of lower volume and aerated, and the fluid that does get through and returned back to the reservoir will build pressure there and case it to overflow due to the lack of flow in the system and the back pressure from the pump trying to push fluid the same volume of fluid through the clamped liner high line (pump to hydro).

Vacuum bleeding is a must to get the results that I did if you have the same or similar problem. I had a hand pump already and picked up the adapter pucks off amazon for around 23 coins from OEM tools.

As far as vacuum bleeding I don't have it down to a science as to what precisely to do on your vehicle, but what I did was get the front end up off the ground put the key on the run on position pull 15lb of merc on the reservoir and moved the wheels back and forth first by hand MANY times, watch the gauge, then after that I had the vehicle on and did the same thing just using the steering wheel and watching the vacuum gauge, it'll scream for a bit but it should quite down.

One thing I found weird when I thought i wasn't getting anywhere with the bleeding is that when the truck was on and I was pulling vac. i turned it off to go check the fluid level and it burped up a good bit of fluid, i cleaned everything off checked my level and started the truck again to see how it felt and it was silent as could be lock to lock, no whine just some grunt from the pump on full lock, brake pedal returned back with some good pressure. This anomaly made me think that i perhaps had to much fluid in the reservoir and the aeration that occurs in the reservoir above the fluid line could spill out from the normal pressure generated within the reservoir.

I went this morning to pick up some ATF4 for the power steering and checked under my hood since i saw a puddle (granted it was from my job last night since it was dripping all over the box and pitman arm, but the top of the reservoir was wet so i pulled the cap checked the level and cleaned off the surface to monitor any leaks. I haven't done any long drives on it to really heat soak the fluid but i'll try to get out later and follow up on that while monitoring my fluid level. If what im thinking is correct then fluid level played a major part in my symptoms and to much fluid can hinder you in figuring out your issue since the system will spit up "i think" what it does not need. My drive to the parts store was without event and silent on steering and braking though the truck barely got warm so take it as you will.