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1979 4x4 Pickup LSVP quizzer...
Posted: Fri Jan 11, 2019 7:28 pm
by TikiTim
My L/H drive US '79 4x4 Pickup has a "one-in, one-out" LSVP and has NO bleed valve/nipple. Only a decent sized hex on top which, if I undo it, I'm pretty sure will shoot the valve rod and a bunch of springs into the air...! SO the quiz is, Does this need bleeding (in the regular order R/L, R/R, F/R, F/L, LSVP ? Is so how? If not, and I'm bleeding the four wheel cylinders should the springs/axle (and LSPV) be under normal conditions, or is it ok to do it on a lift with the springs/axle hanging way down? The LSVP seems to be working just fine, so I don't want to replace the LSVP, but my brakes are a little spongy so I'm trying to figure how to get them back to normal.
Thanks (Newbie to this Forum)
Tb
Re: 1979 4x4 Pickup LSVP quizzer...
Posted: Fri Jan 11, 2019 9:48 pm
by Likkedis
Hi Tb,
Did you 'consult' YouTube? I'm no mechanic, but it helped me before....
Re: 1979 4x4 Pickup LSVP quizzer...
Posted: Sat Jan 12, 2019 1:43 am
by Mud Dog
Hi Tim and welcome!
If there is no bleed nipple on the LSPV then just bleed as normal (starting with the closest wheel to the master cylinder and moving incrementally to the furthest), but I would do it with weight on the axle so as to open the valve a bit .... with the vehicle on a hoist and the axle hanging the valve will be closing up and restricting the flow, unless the hoist is the type that you drive onto with the vehicle still resting on it's wheels when hoisted.
Brake fluid is hygroscopic and the absorption of moisture affects the hydraulic properties negatively, resulting in spongy brakes. The rate of moisture absorption depends on the climatic conditions as well as regularity of usage but it's usually recommended to replace the fluid annually. Bleed each wheel until you see the new fluid coming through (lighter in colour).
If this doesn't solve the problem (it usually does), then it might be time to look at servicing or replacing the master cylinder.
Good luck.
Re: 1979 4x4 Pickup LSVP quizzer...
Posted: Sat Jan 12, 2019 5:06 pm
by TikiTim
Likkedis wrote: ↑Fri Jan 11, 2019 9:48 pm
Hi Tb,
Did you 'consult' YouTube? I'm no mechanic, but it helped me before....
I been all over the inter web thingy - came up empty!
Re: 1979 4x4 Pickup LSVP quizzer...
Posted: Sat Jan 12, 2019 5:11 pm
by TikiTim
Mud Dog wrote: ↑Sat Jan 12, 2019 1:43 am
Hi Tim and welcome!
If there is no bleed nipple on the LSPV then just bleed as normal (starting with the closest wheel to the master cylinder and moving incrementally to the furthest), but I would do it with weight on the axle so as to open the valve a bit .... with the vehicle on a hoist and the axle hanging the valve will be closing up and restricting the flow, unless the hoist is the type that you drive onto with the vehicle still resting on it's wheels when hoisted.
Brake fluid is hygroscopic and the absorption of moisture affects the hydraulic properties negatively, resulting in spongy brakes. The rate of moisture absorption depends on the climatic conditions as well as regularity of usage but it's usually recommended to replace the fluid annually. Bleed each wheel until you see the new fluid coming through (lighter in colour).
If this doesn't solve the problem (it usually does), then it might be time to look at servicing or replacing the master cylinder.
Good luck.
Thanks Mud Dog - you say “nearest to furthest,” I’ve always done furthest to nearest...? Following advice from other Yota Heads... I wonder what the wisdom is for each method?
T
Re: 1979 4x4 Pickup LSVP quizzer...
Posted: Sat Jan 12, 2019 6:26 pm
by Mud Dog
You know, I'm sure that will work just as well, just that your first bleed will be long and the others thereafter short.
Re: 1979 4x4 Pickup LSVP quizzer...
Posted: Wed Jan 30, 2019 1:27 am
by TikiTim
Thanks. Ended up bypassing LSVP, and removing the rod and mounts. The brakes work great!
Re: 1979 4x4 Pickup LSVP quizzer...
Posted: Wed Jan 30, 2019 7:17 am
by Tim86
Tim post a pic of your ride please, keen to see the variation in older models from your side of the world to ours:)