Hissing sound (1 Viewer)

[Tachycardic]

I just noted a hissing/vacuum sound coming from the driver’s footwell. It goes away when pressing on the brakes. It returns when I let go of the brake pedal. Brakes work fine, vehicle drives normally, and there's no CEL. Nothing leaking underneath. Thoughts?

 

[BILT4ME]

Check the hose to the brake booster. Could be loose or leaking and maybe the check valve failed.

Or the booster is getting ready to fail and leaking such that it sucks from the push rod side

 

[Rifleman]

Could be a Vacuum leak in the power brake booster diaphragm. To test that idea you'd need to disconnect the vacuum hose from the engine to the brake booster. Next apply a vacuum directly to the booster, then check to see if the booster holds that vacuum.

 

[Shipwreck]

Leaking brake booster. You may eventually notice increased pedal pressure or slight loss of braking power.
See here:

New Toyota Land Cruiser LX450 OEM Seiken Brake Booster with Gaskets 44610-60792

New 80 series, FZJ80, FJ80, 1991, 1992, 1993, 1994, 1995, 1996, 1997, brake, brake booster, OEM, Seiken, japan, 44610-60792

www.cruiseryard.com

 

[Tachycardic]

Could be a Vacuum leak in the power brake booster diaphragm. To test that idea you'd need to disconnect the vacuum hose from the engine to the brake booster. Next apply a vacuum directly to the booster, then check to see if the booster holds that vacuum.

The hose to the brake booster is in good shape and I just put on new hose clamps as the old ones looked a bit ratty. The check valve is loose. I'm going to replace this first. I'm going to order the following; please let me know if this is correct:

44730-28010 (valve)
90480-24015 (grommet)

Thanks.

 

[woodsman 44]

lol, The first thing to come to mind when you said hissing was Elf

 

[Tachycardic]

I just wanted to double check that all I have to do to change the check valve is to pull it out of the booster. Install the grommet to the end of the valve and press fit. Then reconnect the hose?

 

[atomicshawn]

Just had same issue. Brake booster.

New Toyota Land Cruiser LX450 OEM Seiken Brake Booster with Gaskets 44610-60792

New 80 series, FZJ80, FJ80, 1991, 1992, 1993, 1994, 1995, 1996, 1997, brake, brake booster, OEM, Seiken, japan, 44610-60792

www.cruiseryard.com

 

[Tachycardic]

Replaced the check valve and rubber grommet with OEM parts. Still have the hissing sound. Guess it's time to bite the bullet and buy the new brake booster. Dang, every time I get close to being able to afford a roof rack, something pops up...

 

[Tachycardic]

The old remanufactured brake booster was replaced with a new OEM one and the hissing is gone. Thanks for all your help!

I've saved a bunch of money thanks to this forum and I'm so grateful that I can pretty much find everything I need for my cruiser here. I think it's time to become a silver star member...