Air Bags

Submitted: Friday, Feb 25, 2011 at 09:07
ThreadID: 84596 Views:2393 Replies:7 FollowUps:0
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I have recently fitted a pair of air springs to the rear of my 80 ser L/C. The air springs are inflated by a compressor but both springs are inflated at the same time. My concern is that when going around a bend or corner air could be transferred from one spring to the other as there are no check valves to stop this happening. Are my concerns justified? If so how have other people overcome this problem?
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Reply By: Member - Tour Boy ( Bundy QLD) - Friday, Feb 25, 2011 at 09:53

Friday, Feb 25, 2011 at 09:53
I would be more concerned that when inflated the brake proportioning valve won't allow more pressure to the rear brakes when loaded like it should. It works by a rod attached to the diff moving up an down when the vehicle is loaded (ie lower) it allows more pressure to the rear brakes. Imagine a fully loaded vehicle and a trailer on the back having 80% of the braking done by the front axle only.
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AnswerID: 446516

Reply By: Alloy c/t - Friday, Feb 25, 2011 at 10:02

Friday, Feb 25, 2011 at 10:02
Polyairs or Firestone in coil , should have independant air lines so that as 1 side coil is compressed no air transfer to the other side , sack the bloke that did the fitting as he obviously did not read the fitting instructions ,,lol.
AnswerID: 446517

Reply By: Member - Alastair D (NSW) - Friday, Feb 25, 2011 at 10:56

Friday, Feb 25, 2011 at 10:56
I have Polyairs and as already said they have separate connections. In reality given the small diameter of the hose I doubt that much air would be transferred during a corner but they should not be joined. As said I would go back and have the installation done properly.

AnswerID: 446521

Reply By: Ruffy-Dan - Friday, Feb 25, 2011 at 13:16

Friday, Feb 25, 2011 at 13:16
Your concerns are relevant.
Especially on long sweeping bends the air will transfer and the vehicle will slowly lean. They need to be plumbed to seperate circuits or have check valves.

AnswerID: 446527

Reply By: Member - Craig F (WA) - Friday, Feb 25, 2011 at 17:11

Friday, Feb 25, 2011 at 17:11
If you are using a onboard compressor to inflate you could put a one way valve going to each bag with a branch in the line to deflate. I have mine set up with air fitting to each with a valve inbetween to balance the bags when inflating.
AnswerID: 446544

Reply By: Member - Rodney B- Saturday, Feb 26, 2011 at 10:01

Saturday, Feb 26, 2011 at 10:01
Yep they need to be separated as advised.
I have the Coil Rites on my 80 and have not had any problems with the proportioning valve. Mind you I only use the air bags to level the load not raise the rear beyond normal. I tow both a caravan and camping trailer (not at the same time of course) in some extreme country so am pretty confident that the brakes work fine.
Add a check valve if you can't separate the lines.
AnswerID: 446594

Reply By: Who was that again? (Vic) - Saturday, Feb 26, 2011 at 17:34

Saturday, Feb 26, 2011 at 17:34
Ray, I have Firestones as a spring replacement in the back of the Toyota and I usually put air in one side and use a balancing tap between the two valves. I can use it open for off-road for better articulation of the axle or closed on the road, so that the sway bar and the air springs operate as they should.

The tap open allows a bit more body roll in a road situation, like our old Rangie used to, and that can be disconcerting!
AnswerID: 446641

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