How to adjust brake pistons on a 2009 Argo Frontier 8x8?

[Tiphinaqtuq]

Hello 6x6 World,
I am trying to diagnose and fix my Argo's habit of pulling to the right. There have been a lot of very helpful threads ( to those who contributed to them) on the subject. I would like to try something referenced in post 18 of the thread http://www.6x6world.com/forums/argo-...html#post40117 which suggests that backing off a brake piston may help the situation.

I would like some help with this procedure. I'll start with the simplest question: is this suggesting I alter the master cylinder, or one of the cylinders at the brake pads? It would make sense that I am adjusting a pad cylinder, specifically the cylinder on the side I am pulling to (Argo pulling right, release the right brake cylinder a bit) - am I on track so far?
Next, can I get help with the adjustment process? Is it the procedure detailed in section 7.3.7 of the operator manual, or is it somewhere in the service manual? I only have the 05/06 service manual and it would appear that the steering / braking system has changed significantly since then.

Thanks to anyone who can get me pointed in the right direction.

For anyone else working through a pulling to the side issue, here are some helpful threads to read:

http://www.6x6world.com/forums/argo-atvs/7416-argo-pulling-right.html

http://www.6x6world.com/forums/argo-atvs/15914-argo-pulls-right.html

http://www.6x6world.com/forums/argo-atvs/3111-help-argo-pulling-right.html

http://www.6x6world.com/forums/max-atvs/16255-pulling-right.html

[msafi65]

If the vehicle is pulling to one side from brake pressure that side caliper and rotor should be much hotter than the parts on the other side after a short ride. Be careful checking temp the parts can be extremely hot. If one side is hot the pushrod to the master is to long so the fluid cant return properly.This usually causes the brake to lock when hot. Shortening the pushrod will allow fluid to return through the port in the master cylinder. I usually find a vehicle that pulls to one side has at least one big tire on the fast side. Over inflation can make tires grow3-4 inches in circumfrence. A fabric tape from the sewing room and all tires at same pressure will tell the story. Ive had vehicles with 30 lbs of air in the tires. these tires stay very large after being inflated that much. hope you find the problem.

[shizzles2]

Does it do this immediately after starting, or is it after you have been driven for a bit?
also do you have a brake fan?
just asking because i also had this problem a few times in my argo because the brakes overheated and locked on, this was easily fixed after we wired up the brake fan.
if there is not one already in your argo then adding one definately makes a difference. make sure it's wired to a seperate switch though or the battery runs down when your engines idling.hope that helps.

[Tiphinaqtuq]

Fan and cooling diagnostic

Does it do this immediately after starting, or is it after you have been driven for a bit?

The right pull happens immediately after starting. No change after driving for a while, it neither gets better or worse. At first I thought it got worse with time, it appears I just get tired of correcting for it really quick.

also do you have a brake fan?

Yes, a brake fan comes standard on this model. It is wired to come on with the key in the run position. After reading your post, I checked in to its output and noticed that airflow on the left hand side is lower than on the right hand side. This makes sense because the hose from the fan connects on the right hand side. Because the pull is to the right and the right has superior cooling, I do not think this is the origin of my problem. Thank you for pointing me to check the cooling of the brakes, I see how important that could have been.

[Tiphinaqtuq]

No steering input diagnostic

If the vehicle is pulling to one side from brake pressure that side caliper and rotor should be much hotter than the parts on the other side after a short ride.

If I could ask for some clarification please, do you mean after a drive with no control input or a drive of approximately equal left and right steering? I took the Argo out this evening and drove for 2 minutes with no steering input. I touched the brake discs and both were cold. Several repeats resulted in the same cold discs, one time the left disc was warm, probably as a result of having to turn around to make the next run. If I understand correctly, this suggests that the brakes are not the problem, doubly so if the left is warm - is it correct that warm left wouldn't match a pull to the right?

I usually find a vehicle that pulls to one side has at least one big tire on the fast side. Over inflation can make tires grow3-4 inches in circumfrence. A fabric tape from the sewing room and all tires at same pressure will tell the story.

I just received a high quality low pressure dial gauge (had a lousy pencil gauge before) so I can check this properly now.

Ive had vehicles with 30 lbs of air in the tires. these tires stay very large after being inflated that much. hope you find the problem.

Oooooooh, this may be the issue. The centre rear tire on the left hand side got a puncture which was fixed with a plug, but was leaking and I didn't know if the problem was the plug or something else. It was briefly inflated to 20lbs and doused in soapy water in an attempt to find the problem. I'll see if the tape measure tells the rest of the story. Thanks for your well wishes, I'll post when I have the results.