hydroboost troubleshooting help

[mblaney]

Well I am pretty sure it is hooked up correctly... with the preformed lines I am not sure if it is possible to get wrong but I will double check.

I decided to order a new PS pump and lines (relatively cheap) - plus I ordered the pump for an F-Superduty so I will have a spare reservoir with two return ports .

If a restriction is causing heating my first thought was the pressure bypass in the pump; that might also explain why I don't have any power steering at idle.

 

[Snowmanw900]

That’s what came stock with the Fsuperduty, I’m not sure if they ever made a 1-1/4”mc, I’ve only seen 1-1/8, 1-5/16 and the newer trucks run a 1.5” mc which is what I’m running with an 08 booster as it won’t fit the older boosters.

What year of truck did you put the 08 booster and MC on?

 

[laserjock]

Be careful adding a big cooler. I looked at using the trans loop in the rad and I think it was bikemaker said he tried that and had starvation issues.

I pump issue could explain what you are seeing. Sounds like you are aerating the fluid at high RPM.

 

[Golden Helmet]

Well I am pretty sure it is hooked up correctly... with the preformed lines I am not sure if it is possible to get wrong but I will double check.

I decided to order a new PS pump and lines (relatively cheap) - plus I ordered the pump for an F-Superduty so I will have a spare reservoir with two return ports .

If a restriction is causing heating my first thought was the pressure bypass in the pump; that might also explain why I don't have any power steering at idle.

If it actually does come with the dual returns, please let us know! I've seen the listings before that say they have two returns, but I've heard from others that they actually come with just one. I want to get another bracket, pump, and dual return reservoir set up and ready to go incase my pump dies in the middle of nowhere. Just pull the old bracket off with the pump, throw the new one in, fill and go.

 

[Macrobb]

I'd really be thinking crushed line or something's backwards. If I can have a SD hydroboost unit mounted to a stock '88 F-250 MC with the stock, single-return pump work...

Getting hot on the highway(with nothing being used) really sounds like a restriction to flow.

 

[Garbage_Mechan]

Three things I would check: Be sure the MC piston returns all the way. I loosen mounting nuts and slide the MC back while looking at intake port in bottom of reservoir. If piston moves there is not enough clearance and fluid cannot completely return to reservoir causing brakes to drag af fluid heats up and expands.

 

[Garbage_Mechan]

Second, old brake hoses have given me fits over the years. They swell internally and become unwanted residual check valves. Hard to diagnose, sometimes you can physically tell, sometimes not.

 

[Garbage_Mechan]

3rd and most likely ( and assuming your lines are not crossed as mentioned above) is that there is a power steering return line flow issue. The HB unit is sensitive to restriction in the return flow and will drag the brakes if there is residual pressure in the return line from the booster.

 

[Garbage_Mechan]

Also you mentioned loss in steering assist. This could be a key part of it. Solving this may fix the dragging brake issue.

 

[Garbage_Mechan]

One last thought. I recall at least one instance where the person was running the original one return reservoir with a tee. He had similar issues as yours and solved it swapping in the correct reservoir. Never saw a pic of the tee setup but it must have caused enough restriction to cause the HB to drag.

 

[chillman88]

One last thought. I recall at least one instance where the person was running the original one return reservoir with a tee. He had similar issues as yours and solved it swapping in the correct reservoir. Never saw a pic of the tee setup but it must have caused enough restriction to cause the HB to drag.

I ran like this on my Chevy for years with no issues but I was always told to be mindful that the HB goes "straight through" and the steering gear goes to the T. I don't really see why that would make a big difference but

 

[mblaney]

Thanks for the feedback. I do not have dragging brakes so I am not concerned about the MC or lines, calipers, etc (also, I put 100% new on a few years ago, full SS lines front to back, new flex hoses). My only symptoms is excessive heat, especially at higher engine rpms (cruising on highway).

I have the two return port reservoir so return pressure shouldn't be a problem.

I have ordered a new PS pump, new HP lines... I think my PS pump is original so it's probably a good idea to change... only $60 CDN for the new one.

I have scheduled Saturday to work on this... will post results here!

 

[Macrobb]

I have ordered a new PS pump, new HP lines... I think my PS pump is original so it's probably a good idea to change... only $60 CDN for the new one.

You might want to get one of those PS filters too, just in case. They are generic filters that go inline in the return side(probably steering return, not HB return for you) and keep crud and bits from wearing out your new pump.

 

[NorCaNJD]

I did this conversion about 2 years ago in my 88 6.9
Pulled the HB out of an astrovan at a picknpull.
I installed it and it didn't work! Brakes were as if no booster was present and fluid got really hot. My vacuum booster failed so i wasn't too bummed. I did some research and found that the check valve in the HB clogs easily, bought a rebuild kit and it ended up working. The pedal still returns slow so my old dirty gear box probably let loose some gunk that made its way to the new check valve but my brakes work fabulously.
Wish I got the psp with extra reservoir as if I turn my wheels too much with the truck not running my fluid overflows.
I bent some soft copper as an auxiliary cooler and just teed into the return to the psp.

 

[PROFG]

Can get following for planned Hydroboost conversion. Good idea or keep looking for donor wih ALL the parts? Thanks for any help.
2000-2003 Ford 7.3L OEM hydroboost NIB $100