Hello everyone!
This will sound like a stupid question to more experienced Hydro-Citroen people, but here goes!! I see from various things i read that there are two types of hydraulic pump fitted to the later Hydro-Cits. Could someone explain to me the differences please? I notice from my own pump that there appears to be 6 pistons arranged in a radial fashion that form one pump, but allegedly there are another 2 pistons somewhere else to form another. I read somewhere that it is kind of "two pumps in one." I'm just asking out of curiosity really!<img src=icon_smile.gif border=0 align=middle>
Thanks in advance, best regards, Rich. Keep it Citroen!!<img src=icon_smile_big.gif border=0 align=middle><img src=icon_smile_approve.gif border=0 align=middle>
6+2 Hydraulic pump!! (?)
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Dave Burns
- Posts: 1915
- Joined: 14 May 2001, 05:30
- x 2
Hi Rich, those six piston's supply oil solely to the power steering, the other two supply oil to the brakes and suspension via the accumulator.
Early hydrocits had a flow distributor valve to split the single output from the pump between the power steering and the main accumulator.
Because these car's would sink after a while, it was necessary for the suspension to have a high output pump driving it, which is why they rose again very quickly as soon as the engine was started, a high output is also required by the power steering.
The anti-sink suspension of later models does not place high volume demands for oil on the pump during normal operating conditions, because the car body no longer needs to be raised from very low positions, a pump with a much lower output to operate the suspension and brakes was desirable.
The power steering however requires a much higher volume of oil to operate it, but rather than use the sometimes troublesome flow distributor valve to split the suply, the decision was obviousely made to ditch it in favour of the more efficient and reliable 6+2 pump, with high volume output for the steering and low volume output for the rest of the hydraulic system.
Dave
Early hydrocits had a flow distributor valve to split the single output from the pump between the power steering and the main accumulator.
Because these car's would sink after a while, it was necessary for the suspension to have a high output pump driving it, which is why they rose again very quickly as soon as the engine was started, a high output is also required by the power steering.
The anti-sink suspension of later models does not place high volume demands for oil on the pump during normal operating conditions, because the car body no longer needs to be raised from very low positions, a pump with a much lower output to operate the suspension and brakes was desirable.
The power steering however requires a much higher volume of oil to operate it, but rather than use the sometimes troublesome flow distributor valve to split the suply, the decision was obviousely made to ditch it in favour of the more efficient and reliable 6+2 pump, with high volume output for the steering and low volume output for the rest of the hydraulic system.
Dave
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Rich
- Posts: 103
- Joined: 26 May 2002, 23:59
Hello Dave,
Thank you very much for that mate!<img src=icon_smile_big.gif border=0 align=middle><img src=icon_smile_wink.gif border=0 align=middle><img src=icon_smile_approve.gif border=0 align=middle> Everything has become clear now!
Best regards, Rich.<img src=icon_smile_big.gif border=0 align=middle>
Thank you very much for that mate!<img src=icon_smile_big.gif border=0 align=middle><img src=icon_smile_wink.gif border=0 align=middle><img src=icon_smile_approve.gif border=0 align=middle> Everything has become clear now!
Best regards, Rich.<img src=icon_smile_big.gif border=0 align=middle>