23 replies to this topic

[kez_19]

hi
well i am repairing a friends mk1 and i accidenteley cut through the hydrolastic pipe so i have ordered a new one but living in sweden there are not very many pumps around to fill the system again.

i have read on the internet about building my own parts to make my own pump and it looks like i should be able to make it without too many problems but my question is how strong does the vacuum pump need to be will one from a vacuum sealer work or do i need to go up in size like the ones found in inflatable beds that can deflate themselves or does it need to be more industrial

thanks for the help

michael

[Ethel]

I've not seen a pump with a vacuum function, even the original pump used in rover dealers was just a manually operated hydraulic affair. The simplest solution I've seen is a converted grease gun.

hi
well i am repairing a friends mk1 and i accidenteley cut through the hydrolastic pipe so i have ordered a new one but living in sweden there are not very many pumps around to fill the system again.

i have read on the internet about building my own parts to make my own pump and it looks like i should be able to make it without too many problems but my question is how strong does the vacuum pump need to be will one from a vacuum sealer work or do i need to go up in size like the ones found in inflatable beds that can deflate themselves or does it need to be more industrial

thanks for the help

michael

[kez_19]

yeah i have seen this but it says that when fitting a new pipe it needs to be a vacuum in the pipe before filling it with the liquid

[Ethel]

I've only played about with hydrogas Metros, the pipe on them is just brake line, and didn't find it necessary. I'd have thought prefilling and bleeding would work better. You can get a half decent vacuum out of a fridge condensor pump. Just reversing the piston cup on a foot pump or bicycle pump would be easy.

yeah i have seen this but it says that when fitting a new pipe it needs to be a vacuum in the pipe before filling it with the liquid

[kez_19]

was looking at this that needs a motor but i dont suppose it needs a big motor

or
this which dosent have a motor but is it powerful enough ??

michael

[Ethel]

I bet looking fir vac pumps online was interesting

Can't see any reason why it would matter if a positive displacement pump uses a motor or hand operation. It'll just be slower.

was looking at this that needs a motor but i dont suppose it needs a big motor

or
this which dosent have a motor but is it powerful enough ??

michael

[kez_19]

ok then how much vacuum do you think i need is there a certain amount needed ??

[Ethel]

You're just trying to displace any trapped air - swapping it for hydrospastic fluid will be more effective. Same as bleeding brakes.

ok then how much vacuum do you think i need is there a certain amount needed ??

[midridge2]

there are 2 types of pumps you can buy, one just pumps the fluid in and the other has a vacuum pump fitted, its drawn out with a hand operated lever.
all the old churchill pumps that the bmc etc garages used had the vacuum affair.

[kez_19]

so i should be able to as i see it pump in the fluid in one end and leave the pipe open a tiny bit at the other end and when the liquid starts to come out at the non pumped end close that nut and then take the other end and build up the pressure but pumping air in the other end with a normal air pump

will this work or am i way off??

michael

[midridge2]

no, you dont pump air in.
you need to pump out the air first, the tank on the pump is pumped up first and the valve opened and the fluid goes in under pressure you then pump more fluid in to get the car up to the height you want, the haynes book gives the pressure to pump it upto but the recommended thing to do is by the height not pressure.
doing it the way you have said the fluid will shoot out of the open nut but you will still have air in the front displacer.

[kez_19]

ok now i get it i am just a bit unsure as to how much i need to pump out is there some sort of measurement just so that i know how big the pump needs to be

[midridge2]

do you mean for the vacuum or for the pressure of the fluid going in?

[kez_19]

well both really

[midridge2]

i will have a look later tonight for the vacuum one but the pressure one is around the 250-325 psi.