Volvo penta tilt trim bleeding

[frazion]

Ok, here’s a puzzle…

DP-G - redid the seals on the rams, got a new ‘down hose’ and hooked it up(didn’t do any special priming or anything), filled up the reservoir and trimmed up and down to try to bleed as per the rules.

going up to max trim, the trim pump changes tone and can’t pump anymore as expected due to the hydraulic stop.
Trimming back down I can hear air in the system and when it’s trimmed in all the way, the pump just keeps going along with the air fizz noise . After 5 seconds or so the tone changes and the air fizz goes away but the trim pump just keeps pumping away.
The rams are spongy, I can lift the drive a bit by hand.

map, definitely air in the system but all my pipes are tights and no leaks so it doesn’t look like it sucking in air from the outside.

any one got any thoughts? Is there an alternative bleeding method?

 

[simonfraser]

the reservoir in the pump is topped up ?

 

[frazion]

Yup, topped up to max,

the reservoir in the pump is topped up ?

 

[simonfraser]

i'd be tempted to slightly undo one of the higher up joints, be prepared for some spillage and see if you can 'unlock' the air by running the pump again

 

[frazion]

At the pump or the cylinders?

 

[simonfraser]

you'd want to expell the froth, not suck in the air to get rid of the air lock in the pump
not sure you can easily predict which way it runs, so i'd undo one connection and see what happens, expell is good imo
a higher point likely better, but somewhere you can manage the spill
i'd look at one of the upper hoses to a ram IF they undo without damage
else at the pump, undo one, if it sucks reverse the direction of flow and you should get froth ....
let us know

 

[frazion]

I’ll be heading over shortly to attack this problem. Launch date is this Friday and this is a Last minute issue, so really want to avoid the rams if at all possible!

so plan is, I’ll remove the trim pump connector, feed it into the reservoir directly and run the pump, do that for both connectors being sure to not suck in any air and if that doesn’t work it’s down to loosening the connectors at the rams and making a mess to try and bleed.

urgh, ram hydraulic connectors give me the willies.

 

[simonfraser]

'feed it into the reservoir directly and run the pump, do that for both connectors being sure to not suck in any air and if that doesn’t work'

thats not gonna work as the pump will blow all the oil out of the now disconnected pump ports, you'll def make a mess

 

[frazion]

Thanks, not sure I understand your suggestion then regarding undoing connections?

 

[simonfraser]

just loosen one connection off, run the pump, it will either blow froth out, good or suck air in, bad

 

[frazion]

Ah, loosen rather than disconnect!

 

[simonfraser]

that's what i said

'i'd be tempted to slightly undo one of the higher up joints, be prepared for some spillage and see if you can 'unlock' the air by running the pump again '

 

[frazion]

that's what i said

'i'd be tempted to slightly undo one of the higher up joints, be prepared for some spillage and see if you can 'unlock' the air by running the pump again '

So that’s been fun. Couldn’t loosen anything on the cylinders so didn’t worry about those, loosened the pipes on the pump and bled there, no joy. Pulled the trim end caps, checked that the seals which I had just replaced these past few months were not compromised…nope.

pulled the pump apart to check that the check valve balls etc were not fouled..all crispy clean.

confused, I pulled the pump motor off and apart, got confused why it had a pile of o rings (which were goobered) when it wasnt sealing anything. Then I read the note on the motor…make sure filled with oil before operation…well that would explain the o rings if the motor is supposed to be full of oil and also explain why the motor sounded like it was struggling. New pump motor ordered and I wonder if when it is sealed onto the pump body if that will solve the issues bleeding !

 

[simonfraser]

'make sure filled with oil before operation'
that'd be kinda obvious, who filled the system before running the pump ?

p.s. goobered - excellent term !