Max Flo o-ring kit

[Konigballer]

Hey guys,

Found this o-ring rebuild kit for my Max Flo 4500 and was wandering if it would mess it up? Will buna o-rings work for long in that thing?

http://cgi.ebay.com/Max-Flo-Regulato...:B:SRCH:US:101

[Spider-TW]

I have an HNBR (green buna HVAC) oring on the piston in my max-flo inline, which is doing well for several cases of paint now. The urethane one seemed to leak, but it's hard to tell on that design when you have a small leak. Any of the four operating seals could be leaking.

The green orings are about the buna equivalent of urethane (including $), but you can find them at the auto parts store. The tiny seal in the center of the piston and the poppet ring probably needs to be urethane for the cushion; you may be able to get away with buna for a while on the other seals. Mine kept getting dirty before the seals wore out, most likely due to the air at a particular field.

I haven't looked at the manifold diagram, but the poppet on the inline is loctited together and you have to cook it pretty well to loosen it up. It will break otherwise.

You at least need to match the durometer of urethane with the buna. I think most of the rings on the diagram are 90 aren't they? I worry about those kits being full of 70s, which is as much a durability problem as the material change.

[blake20]

my $.02

Don't waste your money on that kit. it has too many urethane O rings and not enough buna o rings. Especially the on/off O ring that always goes bad. I bought that kit and was not happy at all.

[Konigballer]

what do ya'll suggest for o-ring kits for a Max Flo 4500? Where do you find them?

[Spider-TW]

There are factory kits still available from the bastion of evil itself.

I haven't seen a kit that looked correct that wasn't some vintage from the factory. Mine came with some extra seals that didn't help much. Overall cleaning, polishing the hole in the on/off plug and changing out the piston o-ring with the HNBR o-ring fixed most of my problems. On occasion (about once an event) it will vent a little hiss out of the top, but I can turn it off and back on again and it stops. Considering the SP guys tried three times to fix it when it was worse, I'm sticking with it as it is. They would replace some seals and re-grease it to no effect. I finally realized that they never swabbed out the inside. After I cleaned it out, it worked much better.

Another ebay kit