hydro boost ?

[TrentNell]

i am putting a new hydroboost in this weekend ....... anyone done one yet? my question is wether you had to bleed/purge the ABS acumulator( tech2 required ) or if a standard bleed was enough ? i havent done one yet on a dmax . any other tips

 

[stacks04]

i am putting a new hydroboost in this weekend ....... anyone done one yet? my question is wether you had to bleed/purge the ABS acumulator( tech2 required ) or if a standard bleed was enough ? i havent done one yet on a dmax . any other tips

eta: you should not have to bleed anything brakes related. you never disconnect the master. just the power steering system. hope this helps.


Removal Procedure

1. Apply the park brake and block the wheels.
2. Disconnect the inlet hose, the steering gear, and the return hoses from the booster assembly.
3. Remove the master cylinder. Refer to Master Cylinder Replacement .
4. Remove the stop lamp switch and the pushrod.
   
   
   
   
5. Remove the booster to bulkhead nuts.
6. Remove the booster assembly.
7. Remove the gasket.

Installation Procedure

1. 
   
   
   
   
2. Install the gasket.
3. Install the booster assembly.Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
4. Install the booster to bulkhead nuts.Tighten
   Tighten the nuts to 36 N·m (26 lb ft).
5. Install the stop lamp switch and the pushrod.
6. Install the master cylinder. Refer to Master Cylinder Replacement .
7. Connect the return hose, the steering gear, and the inlet hoses.
8. Bleed the hydraulic booster system. Refer to Power Steering System Bleeding in Power Steering System.
9. Release the park brake and unblock the wheels.

© 2009 General Motors Corporation. All rights reserved.






Power Steering System Bleeding

1. Important:
   • Use clean, new power steering fluid type only. See the Maintenance and Lubrication subsection for fluid specifications. Refer to Fluid and Lubricant Recommendations .​
   • Hoses touching the frame, body or engine may cause system noise. Verify that the hoses do not touch any other part of the vehicle.​
   • Loose connections may not leak, but could allow air into the steering system. Verify that all hose connections are tight.​
   
   Important: Power steering fluid level must be maintained throughout bleed procedure.
2. Fill pump reservoir with fluid to minimum system level, FULL COLD level, or middle of hash mark on cap stick fluid level indicator.Important: With hydro-boost only, the oil level will appear falsely high if the hydro-boost accumulator is not fully charged. Do not apply the brake pedal with the engine OFF. This will discharge the hydro-boost accumulator.
3. If equipped with hydro-boost, fully charge the hydro-boost accumulator using the following procedure:
   2.1. Start the engine.
   2.2. Firmly apply the brake pedal 10-15 times.
   2.3. Turn the engine OFF.​
4. Raise the vehicle until the front wheels are off the ground. Refer to Lifting and Jacking the Vehicle in General Information.
5. Key on engine OFF, turn the steering wheel from stop to stop 12 times.Vehicles equipped with hydro-boost systems or longer length power steering hoses may require turns up to 15 to 20 stop to stops.
6. Verify power steering fluid level per operating specification. Refer to Checking and Adding Power Steering Fluid .
7. Start the engine. Rotate steering wheel from left to right. Check for sign of cavitation or fluid aeration (pump noise/whining).
8. Verify the fluid level. Repeat the bleed procedure if necessary.

© 2009 General Motors Corporation. All rights reserved.

 

[TrentNell]

thanks stacks i havent looked at it that close yet , just starting to not work too well anymore pedal pushes clear to the floor now with little resistance , much less than my buddies truck , wasnt shure if it was all 1 unit or not hope its the only problem , brakes still work ok so master cylinder seems ok still .

 

[JakeGMCHD]

Done it in about 45 minutes with removing the clip on the pedal and reusing the clip. Didn't bleed anything just slide it forward a little bit carefully. Hardest part is taking the 4 nuts off the Hydro Boost unit inside the cab.

 

[TrentNell]

Done it in about 45 minutes with removing the clip on the pedal and reusing the clip. Didn't bleed anything just slide it forward a little bit carefully. Hardest part is taking the 4 nuts off the Hydro Boost unit inside the cab.

what were your symptoms prior to replacement ? thanks for the info :hug:

 

[S Phinney]

Trent its not hard at all. It will take you about an hour. I had hydraulic fluid that kept wetting my inner fender well. The seal between the booster and the master cylinder was by-passing the power steering fluid (leaking). No real bleeding to be done just turn lock to lock several times after pressing your brakes hard several times.

 

[JakeGMCHD]

My pedal was getting weak then going to the floor. Now it's like a brand new truck stopping with almost no pedal.

 

[bullfrogjohnson]

Anyone ever have the gasket go out? Mine has been leaking since the day I got it. If its not hard I might just knock it out