Whilst bleeding the brakes and changing a couple of spheres on my TZD BX I have noticed that the LHM that comes out is full of small bubbles, the car behaves normally in every way and the reservoir is at the normal level, any ideas?
Stewart
LHM Mousse
Moderator: RichardW
If you're talking about the LHM in the reservoir, after you've released the bleeder on the accumulator, that's perfectly normal.
That bleeder in fact allows the fluid to returmn to the tank via a return line so it's not high pressure & it comes through all full of air bubbles as the return is more air than fluid.
The air simply dissipates via the breather.
If however it's coming from the brake bleed nipples, then that's a different story & is air in the system as it's coming from the HP side of things & normal practice is to keep bleeding until those bubbles disappear.
If they don't; better go looking for the source of air contamination.[:D]
Alan S
That bleeder in fact allows the fluid to returmn to the tank via a return line so it's not high pressure & it comes through all full of air bubbles as the return is more air than fluid.
The air simply dissipates via the breather.
If however it's coming from the brake bleed nipples, then that's a different story & is air in the system as it's coming from the HP side of things & normal practice is to keep bleeding until those bubbles disappear.
If they don't; better go looking for the source of air contamination.[:D]
Alan S
In line with AlanS :
1) check the filter meshes in reservoir. The meshes also have the surprising effect of bursting the air bubbles that returns to the reservoir. If the meshes are split (damaged) the bubbles keeps circulating in the system.
2) Check the large rubber pump suction hose. You can't see it's leaking, as the LHM is under vacuum, thus a leak causes air to get in.
leaks are common on the the studs: hose clamps loose fit, deep surface cracking over the studs, surface hairline cracks when hose bend. PVC hosing (water, even garden) - clean of course - can be used as preliminary replacing.
1) check the filter meshes in reservoir. The meshes also have the surprising effect of bursting the air bubbles that returns to the reservoir. If the meshes are split (damaged) the bubbles keeps circulating in the system.
2) Check the large rubber pump suction hose. You can't see it's leaking, as the LHM is under vacuum, thus a leak causes air to get in.
leaks are common on the the studs: hose clamps loose fit, deep surface cracking over the studs, surface hairline cracks when hose bend. PVC hosing (water, even garden) - clean of course - can be used as preliminary replacing.