Hydroboost Problem.
09-06-2003, 09:46 PM
#1
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Hydroboost Problem.
Just got it all back together and brakes work great.........too well in fact. As soon as the system gets pressure the brakes come on with no pedal pressure. In fact the pedals have been disconnected and still the brakes come on when the engine is fired up. What gives?
09-06-2003, 10:06 PM
#2
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Re: Hydroboost Problem. (Brutus)
Problem solved, but I shouldn't have had to do it. Ended up spacing out the master cylinder with 3 washers per side between it and the booster. Obviously there is an issue with the connecting push rod for some reason. There has to be a better way.
09-07-2003, 07:04 AM
#3
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Re: Hydroboost Problem. (Brutus)
Did you buy the system from hydratech or did you gather the parts on your own.
I am going thru my brakes as we speak and waiting on my calipers to arrive.
I will put everyting back together as original and after all is working fine then i plan on replacing with the hydraboost that i have.
Sounds like the adjustment is off on the rod but as i have not installed it yet myself i can't say for sure.
Norval is a great source of information on this subject. IM or email him and i'm sure he will advice.
Please post your findings here or im or email me so i can learn as well.
Never too much info
I am going thru my brakes as we speak and waiting on my calipers to arrive.
I will put everyting back together as original and after all is working fine then i plan on replacing with the hydraboost that i have.
Sounds like the adjustment is off on the rod but as i have not installed it yet myself i can't say for sure.
Norval is a great source of information on this subject. IM or email him and i'm sure he will advice.
Please post your findings here or im or email me so i can learn as well.
Never too much info
09-07-2003, 07:33 AM
#4
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Re: Hydroboost Problem. (Armstrong)
James...Yes I bought the unit from Hydratech as a reconditioned item. I will say that I had very little time to "tune" the system today before I had to go to work and will have less opportunity to work on it again tomorrow before I have to take the car to have some exhaust work done. Maybe I'm wrong, but I can only see the problem I've encountered as being caused by the connecting pushrod between the booster and the master cylinder. Nothing else makes sense.
The push rod doesn't seem to come out as did the one from the "old" vacuum booster otherwise I'd easily be able to shorten it to suit. Anyhow I hope there is a way out of this situation of having to add spacers as the look is just not right and not me.
The push rod doesn't seem to come out as did the one from the "old" vacuum booster otherwise I'd easily be able to shorten it to suit. Anyhow I hope there is a way out of this situation of having to add spacers as the look is just not right and not me.
09-07-2003, 09:30 AM
#5
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Re: Hydroboost Problem. (Brutus)
I have noticed that mine is real slow to release, but it does fully release. If you lowered the pedal in accordance with the instructions then the problem would have to be the link to the master cylinder since there is no upper stop for the pedal except the internal stop of the booster. Would it be hard to recheck it after a few break in miles? I kind of hope that my problem is tight seals.
09-07-2003, 04:39 PM
#6
Re: Hydroboost Problem. (Brutus)
Just got it all back together and brakes work great.........too well in fact. As soon as the system gets pressure the brakes come on with no pedal pressure. In fact the pedals have been disconnected and still the brakes come on when the engine is fired up. What gives?
The usual culprit is excessive back pressure on the return line circuit, causing a "mysterious" self apply of the brakes when the engine is fired up. This concern usually arises when somebody has installed the T fitting in the return line between the steering and a ps cooler ( the cooler causing a restriction to flow = backpressure, which upsets the internal valving...). In some cases the T fitting isn't installed straight on the run, with fluid returning from the steering being allowed to "blow up the return line". For diagnostic purposes, you could take a seperate hose from the return fitting on the assist unit and put it straight into the mouth of the ps pump to see if your problem clears up...
Check for this condition and let us know :cheers:
09-07-2003, 05:19 PM
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Re: Hydroboost Problem. (Hydratech Braking)
Paul..Thanks for for the advice. My set up is running a T piece adjacent to the P/S pump from the steering box and then up to the booster with no cooler in line. The "top" of the T (i.e. the straight thru end) is the one running in line from the box to the booster with the "lower" part of the T returning to the box. Is it your suggestion that the return line focus more towards the p/s pump than the booster itself?
Also as mentioned above, the brakes do take a little time to release.
Thanks.
Bob
Also as mentioned above, the brakes do take a little time to release.
Thanks.
Bob
09-09-2003, 10:21 PM
#9
Re: Hydroboost Problem. (Brutus)
Brutus - from the sounds of it, atleast in my take on it, is indeed that you have the return line T setup in such a way as to have returning fluid from the steering trying to flow up the hose to the assist unit (to cause an upset of the internal control valve operations / differential pressures). If the fluid from the steering is allowed to return to the steering reservoir straight through the T, there is usually proper operations to be had.
"Just for laugh and giggles - humor me if you must" - run a seperate return hose from the assist unit to the reservoir (with the cap off / straight into the mouth of the ps pump) and let me know what happens.
:flag
Oh yes - remove the washers you are using as spacers and tell me if the car rolls freely with the engine off - if it does, the master cylinder pushrod length is not the problem.
[Modified by Hydratech Braking, 10:24 PM 9/9/2003]
"Just for laugh and giggles - humor me if you must" - run a seperate return hose from the assist unit to the reservoir (with the cap off / straight into the mouth of the ps pump) and let me know what happens.
:flag
Oh yes - remove the washers you are using as spacers and tell me if the car rolls freely with the engine off - if it does, the master cylinder pushrod length is not the problem.
[Modified by Hydratech Braking, 10:24 PM 9/9/2003]
09-10-2003, 02:54 AM
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Re: Hydroboost Problem. (Hydratech Braking)
Brutus - from the sounds of it, atleast in my take on it, is indeed that you have the return line T setup in such a way as to have returning fluid from the steering trying to flow up the hose to the assist unit (to cause an upset of the internal control valve operations / differential pressures). If the fluid from the steering is allowed to return to the steering reservoir straight through the T, there is usually proper operations to be had.
"Just for laugh and giggles - humor me if you must" - run a seperate return hose from the assist unit to the reservoir (with the cap off / straight into the mouth of the ps pump) and let me know what happens.
:flag
Oh yes - remove the washers you are using as spacers and tell me if the car rolls freely with the engine off - if it does, the master cylinder pushrod length is not the problem.
Thanks Paul. I see what you're getting at with the P/S return line fluid. The way I have the T piece lined up the fluid is all but bypassing the P/S pump and is going back to the assist unit at a greater rate/amount than it should, thus upsetting it's internal operations to the point where it's causing 'confusion' with the internal valving.
Before I reset the T piece to a position where the P/S fliud returns basically to the pump, I'll "humour" you and see what the result is from your little experiment first and let you know the outcome.
[Modified by Hydratech Braking, 10:24 PM 9/9/2003]
"Just for laugh and giggles - humor me if you must" - run a seperate return hose from the assist unit to the reservoir (with the cap off / straight into the mouth of the ps pump) and let me know what happens.
:flag
Oh yes - remove the washers you are using as spacers and tell me if the car rolls freely with the engine off - if it does, the master cylinder pushrod length is not the problem.
Thanks Paul. I see what you're getting at with the P/S return line fluid. The way I have the T piece lined up the fluid is all but bypassing the P/S pump and is going back to the assist unit at a greater rate/amount than it should, thus upsetting it's internal operations to the point where it's causing 'confusion' with the internal valving.
Before I reset the T piece to a position where the P/S fliud returns basically to the pump, I'll "humour" you and see what the result is from your little experiment first and let you know the outcome.
[Modified by Hydratech Braking, 10:24 PM 9/9/2003]
09-10-2003, 08:46 AM
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Re: Hydroboost Problem. (Brutus)
Brutus there is no way I would run washers between the hydraboost and the master cylinder. If it proves that the output rod is too long from the hydraboost you would be better off removing the master cylinder, taking out the clip, remove the piston, chuck it in a lathe and drill a small amount deeper. I have done this before without a problem and it allows the master cylinder to be bolted tightly against the hydraboost.
I have used the non power master cylinder and it requires a shallower hole. In this case I just make a new piston to the old dimensions but drill the hole less.
Good luck Brutus.
I have used the non power master cylinder and it requires a shallower hole. In this case I just make a new piston to the old dimensions but drill the hole less.
Good luck Brutus.
09-10-2003, 08:59 AM
#12
Re: Hydroboost Problem. (norvalwilhelm)
If for any reason the rod does actually end up needing to be shortened, let me know, as I can provide quick easy instructions on how to remove the master cylinder pushrod for the purposes of length adjustments / shortening. We check each and every assist unit with a rod length checking "go / no go" gauge to insure accuracy, therefore "my money is on the hydraulic side" causing the issues. :banghead:
09-10-2003, 06:02 PM
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Re: Hydroboost Problem. (71'AirStrike)
For those who have been following this thread and are possibly having some doubts regarding the Hydroboost system, I would just like to dispell any fears about it's fittment and/or operation and say that the "problems" I have encountered are in no way attributable to the actual product supplied by Hydratech at all. Moreso the reason behind all this is that I purchased a "line delete" option kit so I have had to devise and connect all new P/S lines myself (because of my "unique" situation of installing one of these units to a RHD vehicle) and in doing so have had to come up with my own version of how all the lines are plumbed. Obviously I haven't achieved perfection just yet, but with the willing and able assistance of Paul from Hydratech, I have no doubt that I'll have it running as well as it was originally claimed.
Stay tuned for the finished results. :yesnod:
Stay tuned for the finished results. :yesnod:
09-10-2003, 06:27 PM
#15
Melting Slicks
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Re: Hydroboost Problem. (Brutus)
Very nice disclaimer Brutus, and you didn't even mention that Paul was holding a gun to your head. :jester
My Hydro-Boost installation went very well and I couldn't be happier with the quality of parts or the service.
Reading what Paul was saying about the pressure return T fitting I wonder if it might be better to get a Y fitting that has one leg of the Y straight?
My Hydro-Boost installation went very well and I couldn't be happier with the quality of parts or the service.
Reading what Paul was saying about the pressure return T fitting I wonder if it might be better to get a Y fitting that has one leg of the Y straight?
09-10-2003, 06:36 PM
#16
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Re: Hydroboost Problem. (1979toy)
Steve...yeah that gun to my left temple completely slipped my mind somehow. :D
Good idea about using a Y piece instead of a T. I had given it some thought, but until I have the Car back here in front of me, I won't be able to devise how I'll set up this system to overcome my dilemma and still come out with it all looking half decent too.
Bob
Good idea about using a Y piece instead of a T. I had given it some thought, but until I have the Car back here in front of me, I won't be able to devise how I'll set up this system to overcome my dilemma and still come out with it all looking half decent too.
Bob
09-10-2003, 07:08 PM
#17
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Re: Hydroboost Problem. (Brutus)
Another thought might be to increase the return line hose diameter from the booster to the pump. I'm not sure how the pump end could be increased in size though. Maybe Paul has looked at the pump end enough to have a thought on it.
09-10-2003, 07:32 PM
#18
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Re: Hydroboost Problem. (1979toy)
Another thought might be to increase the return line hose diameter from the booster to the pump. I'm not sure how the pump end could be increased in size though. Maybe Paul has looked at the pump end enough to have a thought on it.
09-10-2003, 07:44 PM
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Re: Hydroboost Problem. (Brutus)
Brutus this is a shot which you have seen before of my remote tank. Only one return line is seen here but another is on the end. I return my hydraboost directly to the tank with it's own outlet and another returns the power steering. The big line feeds the pump.
Double click to enlarge
[Modified by norvalwilhelm, 6:45 PM 9/10/2003]
Double click to enlarge
[Modified by norvalwilhelm, 6:45 PM 9/10/2003]
09-12-2003, 08:10 AM
#20
Re: Hydroboost Problem. (Brutus)
"unfortunately as it's a dedicated 5/16" line from the steering box"
Hmmm - the 5/16 return line sounds like the culprit, to cause ps system back pressure. Every OE line I have ever seen is 3/8, and for a good reason. How in the world did the return line end up being 5/16 ?
Hmmm - the 5/16 return line sounds like the culprit, to cause ps system back pressure. Every OE line I have ever seen is 3/8, and for a good reason. How in the world did the return line end up being 5/16 ?