Brake bleeding help (1 Viewer)

[sw00py]

I understand the process for the most part, but I'm confused about the 5th bleeding spot (according to Hayes manual), the master cylinder. Do I need to take the cylinder out of the truck to bleed it (bench bleeding I've seen it called). How would you bleed master cylinder? Also in my research I came across this comment in another thread:

"Did you let the master cylinder go dry? If so, you need to bleed it first, refill and then rebleed the rest including the LSPV."

Unfortunately I did let my master cylinder run dry is there anything else I need to do because of this? My truck is a 1984 Toyota Pickup 4x4 base model. I'm pretty sure it does not have a LSPV, but wanted to double check.

Is there anything wrong with this process:

1. Bleed master cylinder (mainly confused about this step)
2. Bleed rear passenger side
3. Bleed rear drivers side
4. Bleed front passenger side
5. Bleed front drivers side.

 

[sw00py]

I looks like there is still fluid in the master cylinder. I completly disconnected the brake line from the front wheels and they were left unscrewed for a couple of weeks. I figured it would have all drained out, but it looks like there is still fluid in there. So do I need to take the master cylinder off to bench bleed or was it not run dry? Thanks! Also if I do need to remove master cylinder should I just replace it with a new one?

 

[aztoyman]

Bench bleeding is for when you are putting a new master cylinder on, new out of the box. You clamp it in a vise to hold it and put a couple tubes typically included with the new master into the outlet ports and back into the reservoir. You fill the reservoir and push on the piston of the master to pump fluid out the ports and back into the reservoir. It's just a way to pump the air out.

On yours, I would just wipe out the dirty reservoir and fill it up with fresh fluid. Then open bleeders and gravity bleed it first. Just to get the system mostly filled. Then bleed it in the order the service manual says.

I would think your truck would have the LSPV. It's the one on the rear that the rod from the axle attaches to.

 

[aztoyman]

To avoid the master cylinder going dry, make sure you monitor the fluid level as you bleed the system. Add more as it gets lower from bleeding. It's easy to lose track while bleeding it. If it runs dry ,you have to start all over because you just let air get in at the source.

 

[aztoyman]

To be clear, NO I would not remove the master cylinder.

 

[gnob]

order is
DS RR
PS RR
PS FT
DR FT
LSPV

as mentioned i would initially gravity bleed, then proceed to pedal.

 

[bkg]

Bench bleeding is for when you are putting a new master cylinder on, new out of the box. You clamp it in a vise to hold it and put a couple tubes typically included with the new master into the outlet ports and back into the reservoir. You fill the reservoir and push on the piston of the master to pump fluid out the ports and back into the reservoir. It's just a way to pump the air out.

On yours, I would just wipe out the dirty reservoir and fill it up with fresh fluid. Then open bleeders and gravity bleed it first. Just to get the system mostly filled. Then bleed it in the order the service manual says.

I would think your truck would have the LSPV. It's the one on the rear that the rod from the axle attaches to.

or if it runs dry. Can be done in the truck easily enough, though. Should only take 10 minutes, give or take.

 

[sw00py]

And if I do need to remove master cylinder to bench bleed, should I just go ahead and buy a new one. I imagine the current one is the same that came with the truck 40 years ago.

or if it runs dry. Can be done in the truck easily enough, though. Should only take 10 minutes, give or take.

Any ideas why there was still fluid in my master cylinder even tho the lines to the front calipers were disconnected for weeks? I figured everything would have drained out.

 

[bkg]

I've personally never seen a master cylinder drain completely via gravity unless the seals were bad.


Edit: take that as a grain of salt.

 

[ToyotaMatt]

I understand the process for the most part, but I'm confused about the 5th bleeding spot (according to Hayes manual), the master cylinder. Do I need to take the cylinder out of the truck to bleed it (bench bleeding I've seen it called). How would you bleed master cylinder? Also in my research I came across this comment in another thread:

"Did you let the master cylinder go dry? If so, you need to bleed it first, refill and then rebleed the rest including the LSPV."

Unfortunately I did let my master cylinder run dry is there anything else I need to do because of this? My truck is a 1984 Toyota Pickup 4x4 base model. I'm pretty sure it does not have a LSPV, but wanted to double check.

Is there anything wrong with this process:

1. Bleed master cylinder (mainly confused about this step)
2. Bleed rear passenger side
3. Bleed rear drivers side
4. Bleed front passenger side
5. Bleed front drivers side.

if its not too late , update your truck to this , and never look back,

- if anyone suggests this is incorrect or bad idea ? there wrong and the ROCKET Science is really,,,,,


why else would EVERY single TOYOTA made now @ 7/29/2023 6:32 AM be just that

 

[ToyotaMatt]

 

[ToyotaMatt]

 

[sw00py]

Bench bleeding is for when you are putting a new master cylinder on, new out of the box. You clamp it in a vise to hold it and put a couple tubes typically included with the new master into the outlet ports and back into the reservoir. You fill the reservoir and push on the piston of the master to pump fluid out the ports and back into the reservoir. It's just a way to pump the air out.

On yours, I would just wipe out the dirty reservoir and fill it up with fresh fluid. Then open bleeders and gravity bleed it first. Just to get the system mostly filled. Then bleed it in the order the service manual says.

I would think your truck would have the LSPV. It's the one on the rear that the rod from the axle attaches to.

Okay, so you were right I do have a LSPV. Bled the 4 brakes and LSPV and I think everythings good. Brake pedal feels stiff and not spongy like it did prior and the brakes engage when I manually turn wheel and press brake pedal. Tomorrow I put the tires on and go for a drive! Only thing that seems potentially off is I can feel a lot more resistance when I spin front drivers side wheel than passenger side. I think I didn't compress brake caliper pistons quite as far on drivers side as I did on passenger side. So there is a bit more resistance between brake pad and rotor. Not such that I cannot turn the wheel, just noticably more than passenger side. I figured tho that that will change as the pads wear.

Thank you again, I really appreciate it!

 

[sw00py]

if its not too late , update your truck to this , and never look back,

- if anyone suggests this is incorrect or bad idea ? there wrong and the ROCKET Science is really,,,,,


why else would EVERY single TOYOTA made now @ 7/29/2023 6:32 AM be just that


View attachment 3386274View attachment 3386275View attachment 3386276

I bled the brakes earlier with DOT 3 Prestone. I don't think I've seen Valvoline brake fluid in my area. Does it make a noticeable difference and what does that difference look like? Do you also use valvoline engine oil?

 

[ToyotaMatt]

Okay, so you were right I do have a LSPV. Bled the 4 brakes and LSPV and I think everythings good. Brake pedal feels stiff and not spongy like it did prior and the brakes engage when I manually turn wheel and press brake pedal. Tomorrow I put the tires on and go for a drive! Only thing that seems potentially off is I can feel a lot more resistance when I spin front drivers side wheel than passenger side. I think I didn't compress brake caliper pistons quite as far on drivers side as I did on passenger side. So there is a bit more resistance between brake pad and rotor. Not such that I cannot turn the wheel, just noticably more than passenger side. I figured tho that that will change as the pads wear.

Thank you again, I really appreciate it!

please let me know if i got this PARTS DIAGRAM RIGHT

1984 4WD pickup

Your doing a great job here , !

MATT

 

[ToyotaMatt]

I bled the brakes earlier with DOT 3 Prestone. I don't think I've seen Valvoline brake fluid in my area. Does it make a noticeable difference and what does that difference look like? Do you also use valvoline engine oil?

its at advabce auto ,$12.39 is 32oz

-

 

[ToyotaMatt]

I bled the brakes earlier with DOT 3 Prestone. I don't think I've seen Valvoline brake fluid in my area. Does it make a noticeable difference and what does that difference look like? Do you also use valvoline engine oil?

yes , in all the fleet ,


do you know for certain the correct viscosity grade for a hot SIAGON Summer

Find your owners manual and this page chart , I want to make certain , for good measure

.

 

[ToyotaMatt]

.

 

[ToyotaMatt]

 

[aztoyman]

swOOpy, there shouldn't be a BIG difference between the two wheels when you rotate them. You're right about it being a little different if one is a bit tighter when first put on. I'd think that would even out after bleeding though. Make sure you don't have a caliper piston hanging up.

You don't have the hub locked on that side ? It's just the drag of the brakes? Tight wheel bearings can do it as well. Just trying to cover the bases.

It definitely shouldn't pull to that side during a test drive.

Anyway, good job going for it with your own repairs. I hope it turns out well.