You need to specify which side of the system you're referring to, and whether it's still using R12 or has been retrofitted for R134a. Additionally, you'd need to give us an idea of what range you're looking at as far as ambient air temperature goes, as this does affect what your pressure readings should be.
Between 55-60 psi
Its in your owner's manual. My 1998 runs about 40 PSI on Highway and 30 PSI at idle. Goes down a little when warmed up. Was a little stronger when new.
30 psi
this might help you: http://www.justanswer.com/questions/194b5-1987-gmc-suburban-4x4
The Yukon is a GMC and the Suburban is a Chevrolet.
on a 1999 gmc 1500 suburban 5.7 l where is the ac condensor
An ECU is essentially the brain for a 1999 GMC Suburban. Without an ECU the truck will not be able to operate at all.
My 99 gmc suburban is stuck in 4 wheel drice low
Suburban
90 million Pascal is about 13,053 psi
03 GMC Sonoma with the 4.3L Engine: @ 1000 RPM - Minimum of 6 PSI @ 2000 RPM - Minimum of 18 PSI @ 4000 RPM - Minimum of 24 PSI 03 GMC Sonoma with the 2.2L Engine: Minimum of 56 PSI @ 3000 RPM
10000LB on the 93 GMC Suburban 2500 with the 5.7L Engine