Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: P. Wyatt Sabourin on September 23, 2012, 02:33:28 pm

Title: Purpose of front airbag air supply pressure regulator?
Post by: P. Wyatt Sabourin on September 23, 2012, 02:33:28 pm
Foretravel installed a regulator in the front airbag air supply.
What is the purpose of this regulator?

I appears that some folks believe the purpose of this regulator is to assure that the front does not raise faster than the rear after engine start with little air pressure.
This regulator on my coach is set to 60psi while the front airbags reach ride height when the pressure in the bags is about 50 psi, at which time the pressure in the air tank is 60psi. when parking, I normally find a level spot then dump all air from airbags to keep entry step as close to the ground as possible. After engine start, as air pressure builds, the rear of my coach has just started raising when the front has reached ride height. So if the purpose of the regulator in the front airbag system is to keep the coach level as air pressure builds - it does not work, so why not just remove it because it is a common source of leaks?

However, if the regulator in the front airbag air supply has the purpose of causing airbag height increases to occur with the same vigor on the front as on the rear when driving, removing it may cause front end upward adjustments to occur more rapidly than upward adjustments on the rear. It is difficult to believe that the front air regulator has this purpose because the front ride height valve provides air into four airbags at 50psi, while each rear ride height valve supplies air into two airbags at 90psi.

So, what would happen if the front airbag air supply pressure regulator was removed?
Title: Re: Purpose of front airbag air supply pressure regulator?
Post by: John Duld on September 23, 2012, 08:36:10 pm
Ask Mark Harvey.
Title: Re: Purpose of front airbag air supply pressure regulator?
Post by: steve on September 23, 2012, 09:06:54 pm
Quote
I appears that some folks believe the purpose of this regulator is to assure that the front does not raise faster than the rear after engine start with little air pressure.
Thats what I've heard as well ... its purpose was so the front did not go up faster than the rear so you did not drive off to soon.  I've never tested to see if its doing that or if it serves some other purpose.

On ours we also have a lifting tag, so there is one other air regulator that Foretravel added, its set to 100psi on that tag lift line.  My assumption is so that it raises slower so the rest of the coach can better respond to that weight shift.

Anyway inquiring minds want to know more, so if find out more please let us know !
Title: Re: Purpose of front airbag air supply pressure regulator?
Post by: gam on September 23, 2012, 11:15:07 pm
I wonder if the reason for the regulator is to limit the amount of force that can be applied to the front air bags? they only support  a little more then half the weight of the rear bags . If there was any leakage on the front lift section of the control block the front air bags could become rock hard and give you a very ruff ride. As to the tag axle they may again be limiting the amount of force that can be applied. To limit speed most systems would use a flow control valve. Gam