Air bag and tire pressure

[So Cal Adventurer]

Yup, excellent posts and information sources...I will tinker with our Tundra/Hawk to see if I can dial this in..first time I have encountered an active proportioning valve that adjusts the front/rear brake bias based on the height of the vehicle bed.

Still the original suggestion mentioned to put a "rake" on the truck seems backwards if that means having the back higher than the front by raising the rear of the truck...

Again, I appreciate the discussion and shared experiences.

Thanks,
Phil

The rake was specifically for steering and handling. I noticed a big difference. I’ll admit, I had no clue the proportioning valve was active like that.

 

[Wallowa]

The rake was specifically for steering and handling. I noticed a big difference. I’ll admit, I had no clue the proportioning valve was active like that.

Thanks for the clarification..I will change one variable at a time and see if I can find the "sweet spot" for handling and braking...also I am still confused when and how the Tundra braking system related to proportioning the brake bias has evolved through the different models..

Regardless, I will run through some options and empirically find what best works with our Tundra and Hawk.

 

[ottorogers]

Til the front and back match.

my back is always higher than the front, even with zero air pressure in the air bags

 

[Wallowa]

my back is always higher than the front, even with zero air pressure in the air bags

Interesting...then why have air bags? I assumed they were to make finite leveling adjustments to raise the rear under a load.

 

[ottorogers]

Interesting...then why have air bags? I assumed they were to make finite leveling adjustments to raise the rear under a load.

airbags were installed before I added 2 leaf springs, I’m going to separate the airbags so I can adjust for weight differences on left and right side, airbags are not as critical now with the new springs, before the new leaf springs I was much lower on the back end

 

[Squatch]

Keep in mind that the mechanical LOAD SENSING PROPORTIONING AND BY–PASS VALVE went away on Tundras around '05-'06.

I think all 1st gens have it. My 2006 double cab does.

 

[So Cal Adventurer]

Keep in mind that the mechanical LOAD SENSING PROPORTIONING AND BY–PASS VALVE went away on Tundras around 2005 or 2006.

Ah.. perfect.. thanks

 

[ottorogers]

OK everybody I finally did it, I separated the two airbags, with two air fillers and separate lines, one side needed 15 more pounds to bring it up to even, I went to 40 inches from the ground to the middle of the fender, about 2 inches higher than the front of the vehicle, I might go down to 39 inches instead, but I will do a test run tomorrow, we are camped down for the night, I sure hope my swaying issue goes away, because even with the new leaf springs I’m still getting sway on the highway, and it’s very unnerving

 

[So Cal Adventurer]

OK everybody I finally did it, I separated the two airbags, with two air fillers and separate lines, one side needed 15 more pounds to bring it up to even, I went to 40 inches from the ground to the middle of the fender, about 2 inches higher than the front of the vehicle, I might go down to 39 inches instead, but I will do a test run tomorrow, we are camped down for the night, I sure hope my swaying issue goes away, because even with the new leaf springs I’m still getting sway on the highway, and it’s very unnerving

Awesome, can’t wait for the updates, I’m 99% sure all the sway will be gone.

 

[ottorogers]

Awesome, can’t wait for the updates, I’m 99% sure all the sway will be gone.

if the sway does not go away, I have no idea what I will do, I have spent a fortune on this track, and I mean a lot of money

 

[Vic Harder]

if the sway does not go away, I have no idea what I will do, I have spent a fortune on this track, and I mean a lot of money

I can't recall ... do you have beefier than stock anti-sway bars in there yet?

 

[ottorogers]

I can't recall ... do you have beefier than stock anti-sway bars in there yet?

there is no stock sway bar, you can buy a TRD sway bar, as an ad—on, which is what I did, if it’s still bad I’ll look into a Helrig sway bar

 

[rruff]

there is no stock sway bar, you can buy a TRD sway bar, as an ad—on, which is what I did, if it’s still bad I’ll look into a Helrig sway bar

Maybe I'm crazy, but I'm planning on taking my front swaybar off. It will be awhile before I can test that with a camper though.

 

[ottorogers]

Maybe I'm crazy, but I'm planning on taking my front swaybar off. It will be awhile before I can test that with a camper though.

i did not know tundras had a front sway bar???

 

[So Cal Adventurer]

if the sway does not go away, I have no idea what I will do, I have spent a fortune on this track, and I mean a lot of money

Yeah, they do. Big one. Not sure why someone would disconnect it

 

[rruff]

i did not know tundras had a front sway bar???

I thought they all did. I'm going to have stiffer suspension with digressive damping, and the swaybar interferes with articulation offroad. But I haven't tried it yet. My old truck didn't have any swaybars though.

 

[ottorogers]

OK, airbags separated, HUGE DIFFERENCE, should have been separate from day one, big mistake on my part, It’s not 100% better, but I would say it’s at least 50% better, the last thing I can do is put BillSteen shocks in, other than that I’ll just have to live with it the way it is, at least I gained a lot by separating the airbags

 

[Vic Harder]

glad to hear it!

 

[So Cal Adventurer]

Glad to hear it Otto!

FYI, shocks aren’t going to help with sway.

I’m a bit concerned reading your post, as I have the same truck and ordered the same camper. I’ll post my notes when it arrives

 

[rruff]

OK, airbags separated, HUGE DIFFERENCE, should have been separate from day one, big mistake on my part, It’s not 100% better, but I would say it’s at least 50% better, the last thing I can do is put BillSteen shocks in, other than that I’ll just have to live with it the way it is, at least I gained a lot by separating the airbags

Can you describe exactly what you are experiencing, and what the conditions are?