What happens if i ditch the hydralic pump?

[meep]

Ahhh lots of replies. Sorry that havent been around been much a work and so on.

So what you are saying is that one could use the mr2 pump for the brakes and just connect the hydralic lines that goes to the steering rack to a catch tank? There shouldnt be any real preassure in thoose then right?

Thnx alot for the replies and thoughts. Its really appreciated.

[Jamo]

I'm sure you can use the mr2 pump to do both the brakes and steering.

[meep]

I'm sure you can use the mr2 pump to do both the brakes and steering.

Coolers. Would be nice to be able to change it later on to no servoed steering if one would want. Im guessing that wouldnt be a problem though?

[Jamo]

Best bet is to head over to www.motorgeek.com and search for mr2 AND pump.

Will bring up a few people who have done it.

[S2central.net]

Why fit that japcrap instead of getting the hydraulic pump repaired ? Its not like the Audi hydraulic pumps fail on a regular basis. Sure some old bombs can be bothersome, but they work for years and years.

Only advantage in an electric hydraulic pump is that it reduces mechanical load on the engine in that there is one less pump to drive with a belt from the engine. Of course there is a side-effect that the electrical hydraulic pump requires additional current draw from the alternator and that saps the engine a little more, but I dare say not by much.

[Graham]

I agree with Paul, unless you dont have room after your upgrades, the standard pump is more than man enough to do the job. You can get a seal kit and overhaul the pump yourself, the only thing you will need to source is thrust washers which can be made at any machine shop. And you might need to borrow a hub puller.
HERE is how to do it

[meep]

Why fit that japcrap instead of getting the hydraulic pump repaired ? Its not like the Audi hydraulic pumps fail on a regular basis. Sure some old bombs can be bothersome, but they work for years and years.

Only advantage in an electric hydraulic pump is that it reduces mechanical load on the engine in that there is one less pump to drive with a belt from the engine. Of course there is a side-effect that the electrical hydraulic pump requires additional current draw from the alternator and that saps the engine a little more, but I dare say not by much.

Well there is one other big advantage. You can place it pretty much where you want.

[meep]

Best bet is to head over to www.motorgeek.com and search for mr2 AND pump.

Will bring up a few people who have done it.

Searched on motorgeek and found a bunch of threads thnx!
I do have one question though. In most of thoose threads they recommend that you use a vaccum servo for the brakes and just use the ps pump for the steering. Should be ok to turn them around. That is use ps pump for brakes and have no servo on steering?

[Graham]

Tha PAS runs at relatively low pressure maybe 5 bar or something like that, the hydraulic assistance on the S2 runs at around 140 bar, so i dont think the pump will be man enough for the job

[meep]

Tha PAS runs at relatively low pressure maybe 5 bar or something like that, the hydraulic assistance on the S2 runs at around 140 bar, so i dont think the pump will be man enough for the job

Hummm Im not following you now.
If the S2 pump runs att 140 bar and the MR2 one runs at 5 bar why does it work on javads and coreys cars?

[Pirvu Eugen]

What about the vacuum servo? I will love to remove the entire hydraulic brake servo system. If I understand right, the electric pump is also hydraulic pump drived by electric motor in place of belt. Has also vacuum pump inside
Sorry I dont know the mr2 pump. I thought that maibe is existing an electric vacuum pump to do the brakes and keep the original hyd pump in place for steering. The maximum pressure for the steering in the s2 pump is around 90 bar not 140, the 150 bar is usd for brakes only, I allwais had problems with leaks only on brake side of the pump tell me if i am wrong.
Thank You!
Eugen

[Graham]

Hummm Im not following you now.
If the S2 pump runs att 140 bar and the MR2 one runs at 5 bar why does it work on javads and coreys cars?

Are they using the pump for steering assistance or brakes?. If it works for the brakes then that must mean that the S2 purely uses the high pressure to store energy, then as it needs it, bleeds it off through a pressure reducing valve, back to low pressure, in which case a low voltage low pressure electric pump will work as in the circuit below:

[meep]

Hmm interesting Love your drawings graham makes it much easier to understand everything!

[S2central.net]

Going by that summary of what is on motorgeek, the electric pump is for providing hydraulic steering assistance only. Additional conversion with a vacuum servo would provide brake assistance.

Some of the recent Audi TDi engines use a fairly compact little vacuum servo for this purpose - its driven from rear of a camshaft so saps the engine a little but not much. This method avoids the problem of needing a beefy 1-way valve to prevent any boost pressure reaching the servo if its connected to the inlet manifold. Would be a non trivial job to fabricate that for the S2 if you wanted but not impossible. Look up the AKE engine (2.5 V6 TDi) if you like more info.

[Graham]

So as i originally thought, the S2 uses high pressure fluid to act as an assistance to intensify brake assistance such as the circuit below.
P.S. I am a big believer of pictures/diagrams as they speak a thousand words