So a year ago (maybe 2) I had a line pop on the hydroboost/power steering system... doing a frantic search for the correct fluid SEVERAL forums suggested ATF+4 so that is what I bought and filled my reservoir with.... It felt right and I am pretty sure that is what I had used in the past.... NOW I have a leak between the hydroboost and the master cylinder... should I flush the system and add back the CORRECT power steering fluid OR should I buy a new hydroboost module? The books have not been helpful because the service manual I bought from Genos does NOT specify the correct power steering fluid... I'm not sure if it is because I was running ATF+4 or if it was just time for the gasket/seal was just time to go... so should I flush the system and prepare for replacing gaskets or should I flush the system in preparation of replacing the hydroboost?

1 hour ago, Tim Waldo said:

Genos does NOT specify the correct power steering fluid... I'm not sure if it is because I was running ATF+4 or if it was just time for the gasket/seal was just time to go... so should I flush the system and prepare for replacing gaskets or should I flush the system in preparation of replacing the hydroboost?

The 2002 FSM states:

CAUTION: Use MOPAR Power Steering Fluid or

equivalent. Do not use automatic transmission fluid

and do not overfill.

Even though you used ATF, it probably didn't cause your leak - after all, you have gotten a lot of miles out of the unit. My personal recommendation is to replace the hydroboost with a NEW unit. They can be purchased at Parts Geek or Rock Auto for a reasonable price. Flush the power steering system and use a quality power steering fluid of your choice.

I replaced my hydroboost a year and a half ago at 393,000 miles (it started to drip fluid). I purchased the Parts Geek unit (new) and it has performed well for the last 10,000 miles. Whichever way you go, make sure the push rod length (hydro to master cylinder) is correct - very important and the manufacturers don't seem to pay much attention to that detail. I had to cut mine shorter to ensure the free play measurement was correct.

• John

Edited yesterday at 02:54 AM1 day by Tractorman

31 minutes ago, Tractorman said:

I replaced my hydroboost a year and a half ago at 393,000 miles (it started to drip fluid). I purchased the Parts Geek unit (new) and it has performed well for the last 10,000 miles. Whichever way you go, make sure the push rod length (hydro to master cylinder) is correct - very important and the manufacturers don't seem to pay much attention to that detail. I had to cut mine shorter to ensure the free play measurement was correct.

• John

can I not just use the push rod that is IN my truck currently? Seems like it would be easier to replace the gaskets/seals and the kit is less than $50

15 minutes ago, Tim Waldo said:

can I not just use the push rod that is IN my truck currently? Seems like it would be easier to replace the gaskets/seals and the kit is less than $50

Of course you can. You asked, "should I flush the system and add back the CORRECT power steering fluid OR should I buy a new hydroboost module?" and you also asked, "so should I flush the system and prepare for replacing gaskets or should I flush the system in preparation of replacing the hydroboost?" I gave you my personal recommendation.

I based my new hydroboost replacement decision on the fact that my OEM hydroboost gave flawless service for 24 years and 393,000 miles. I didn't want to put a seal kit in this unit because, even though it would fix the leak, all of the internal components still had 24 years and 393,000 miles of operation on them. There is sophisticated valving inside the unit and an accumulator that has an unknown state of pre-charge after all the years gone by. I hold high regard for safety in braking components, such as the booster and the master cylinder, so I prefer to buy new - not rebuild or reseal.

• John

6 hours ago, Tractorman said:

Of course you can. You asked, "should I flush the system and add back the CORRECT power steering fluid OR should I buy a new hydroboost module?" and you also asked, "so should I flush the system and prepare for replacing gaskets or should I flush the system in preparation of replacing the hydroboost?" I gave you my personal recommendation.

• John

:) was just confirming the push rod because in your first post you suggested it was potentially complicated installing a new hydroboost. Your logic makes total sense when you look at it that way... I'm now pushing 460k on mine.