Roof pump question

T

thespannerman

Member
 Oldbury, West Midlands
Folks

I have posted on the problem I have with my roof not operating properly. I have replaced the pump/motor (and it’s located in the boot). As the roof closes (lifts) ok, it’s just really slow to open needing a push to get it moving open. I thought I had an issue with the rams, but after some advice from a forum member (number5) I swapped the pump pipe connections over, and then the roof opened correctly, but was slow to close, so the rams must be ok, and it must be the pump not pushing enough pressure out of the one port.

The roof disengages the front locks ok.

So here’s my first question. has anyone had the pump apart, as I thought the pump motor just rotated the pump one way to open, then the other way to close, just circulating the fluid one way then the other. Are there different seals in the pump as i thought it was just a centrifugal pump.

Second question, would the pump release plunger have an effect on movement in just one direction, or when pressed in does it effect both directions.

The plunger on mine isn’t stuck, it moves freely, although it’s not out very far (how far out should it protrude from the valve body?)

Cheers
Al
 
The bypass valve simply opens up the internal channel inside the pump to allow free flow of the oil so there is no resistance when manually opening and closing the roof. By the sound of it your pump is weak on one side as you proved changing the lines over. Not sure there is anything inside that you could replace to refurb it, No5 is your man for further advice on a fix. The little brass button valve head only protrudes maybe a eighth of an inch when fully out.
 
Any issues like this is usually the motors fault what with water ingress into the scuttle, etc etc. I wrote an article explaining how I removed the motor without removing the roof. Its not that easy but it is possible to do it without too much fuss. As the motor internals get gummed up with rust and stuff it becomes less and less effective until it conks out.
https://z4-forum.com/forum/viewtopic.php?f=2&t=130122
 
He has already changed the motor Andrew and relocated it to the boot, it sounds like the pump is weak on one side, awaiting No5 to chip in with suggestions on what to do.
 
colb said:
He has already changed the motor Andrew and relocated it to the boot, it sounds like the pump is weak on one side, awaiting No5 to chip in with suggestions on what to do.
Click to expand...
Ahh yes he did didnt he.... gotta learn to read... The actual bleeding process is a bit hit and miss, might be something like that.... I will now walk away with my tail between my legs...
 
:) It’s ok, I sometimes don’t read stuff properly. With regards bleeding I was told the pump self bleeds, and the oil level looks fine.

I think the pump is weak running in one direction (in my case when opening) but can’t quite understand why when it appears to be a centrifugal pump, so just spins pushing oil either one way or the other.

Al
 
thespannerman said:
:) It’s ok, I sometimes don’t read stuff properly. With regards bleeding I was told the pump self bleeds, and the oil level looks fine.

I think the pump is weak running in one direction (in my case when opening) but can’t quite understand why when it appears to be a centrifugal pump, so just spins pushing oil either one way or the other.

Al
Click to expand...
Does the pump have an internal filter? Sometimes fitted in the end of one of the unions? If blocked it could cause your symptoms? Just a wild stab tbh.
 
I have just dropped the pump out again, and there doesn’t appear to be any filter/mesh on either of the banjos or in the port holes, so if there is a blockage it must be inside the pump housing.

I also split the motor off the pump (as the new unit came all in one complete) and had a look inside, and it does just look like a centrifugal setup.

So still no further forward.

I need to get hold off (or borrow) another pump to prove it’s the pump at fault as right now the supplier is only offering to refund my money on me returning the pump, but that then leaves me with no pump at all.

Al
 
OK, so here's yet another wild stab.
Is it possible the wiring has a high resistance, such that in one direction you're getting full power to the motor and in the other direction not as much?
 
I guess that might be a possibility, but if I can try another pump/motor it might prove the wiring is ok or not.

Al
 
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