Hunter tc 3500 tire machine - bead blast valve problems

[Supa Dexta]

Picked up this machine and the bead blast didn't work - got a new valve, but once I installed it went from never passing air, to non stop passing air, just a continuous leak and the whole machine can't build air pressure now.

From what I can tell the foot pedal releases air on the back side of the valve, which should trip the seal and allow the exhaust of air to bypass to the bead blast. The way my old valve was hooked up had the barbed ****** on the small end of the valve pointing towards the front of the machine, and the quick connect on the larger side of the valve, and the spring holds the seal in place, preventing air from exiting towards the bead blast.

However, the schematic shows the quick connect and hose barb swapped end for end, which would have the air exiting towards the back of the machine, of which my hoses aren't even long enough for this configuration. But on top of that, the spring within the valve would be pushing the seal open in this configuration, if it was even long enough to reach the seal, but it is not, it just bounces around in the valve body when assembled like that, so it can't be right either.

Does anyone have one of these machine that knows which way the valve should be pointing - hose barb front or rear/ big end of valve forward or backwards.. etc.

Schematic shows the valve (arrow), with hose barb pointing rearwards (red circle), quick connect fwd (green), where as my old valve is like shown in photo. But I've tried a few configurations and it either never works, or always leaks... So either something is missing in the configuration, the spring is wrong, or I'm missing something obvious (not the black line disconnected in photo, was just testing - if I apply even a few lbs of pressure with my mouth the valve closes, but then builds pressure to the point I can't hold it with my mouth, however there is no way to apply pressure to that black line via the machine, with what I can see - only remove pressure via the foot pedal)

 

[greg13]

Part of the fun of a used machine is figuring out and fixing what at least one other person has done to make the machine work. It sounds to me like a spring may be missing somewhere.

 

[Supa Dexta]

Ok I managed to solve it myself - just took some time. I found a tiny hole in the old ruined seal once I cleaned it up, (it was gunked over). This is what allows the pressure to equalize on each side of the seal, and then de pressing the foot pedal bleeds off the back side, tripping the valve to dump.

The new valve is a slightly different set up and doesnt activate from a low pressure situation (no hole in the seal), thats where I was getting hung up. I drilled the tiny hole in the new seal, and it now works as it should!

 

[39CAMC]

^^^^^ You figured it out. I fought through this a month or so back as I was refurbing a few older machines to sell. In my case, the new valve also did not come with a spring, so I had to drill the hole and put the spring in to get it to work reliably.

I guess the Hunter techs know the trick, but it was frustrating to have a whole new valve and it not work.

DaveW

 

[Supa Dexta]

Coulda used you a few days ago! ha There must be versions of this valve that are made with the hole to be triggered by the low pressure condition. Where did you source your valve from? I just got mine from acklands

The parts diagram is also not correct in its layout, for whatever reason.

 

[39CAMC]

Timing is everything.

I got mine at Equipment CIty https://equipmentcity.net/

DaveW

 

[Andy120]

Picked up this machine and the bead blast didn't work - got a new valve, but once I installed it went from never passing air, to non stop passing air, just a continuous leak and the whole machine can't build air pressure now.

From what I can tell the foot pedal releases air on the back side of the valve, which should trip the seal and allow the exhaust of air to bypass to the bead blast. The way my old valve was hooked up had the barbed ****** on the small end of the valve pointing towards the front of the machine, and the quick connect on the larger side of the valve, and the spring holds the seal in place, preventing air from exiting towards the bead blast.

However, the schematic shows the quick connect and hose barb swapped end for end, which would have the air exiting towards the back of the machine, of which my hoses aren't even long enough for this configuration. But on top of that, the spring within the valve would be pushing the seal open in this configuration, if it was even long enough to reach the seal, but it is not, it just bounces around in the valve body when assembled like that, so it can't be right either.

Does anyone have one of these machine that knows which way the valve should be pointing - hose barb front or rear/ big end of valve forward or backwards.. etc.

Schematic shows the valve (arrow), with hose barb pointing rearwards (red circle), quick connect fwd (green), where as my old valve is like shown in photo. But I've tried a few configurations and it either never works, or always leaks... So either something is missing in the configuration, the spring is wrong, or I'm missing something obvious (not the black line disconnected in photo, was just testing - if I apply even a few lbs of pressure with my mouth the valve closes, but then builds pressure to the point I can't hold it with my mouth, however there is no way to apply pressure to that black line via the machine, with what I can see - only remove pressure via the foot pedal)

Hello, I just did the same thing. Replaced the blast valve and the machine just sat there and leaked air from the jets. Control pedals didn’t make anything even flinch. What exactly did you drill?

 

[Supa Dexta]

The seal within the valve that kind of looks like a suction cup. Just a pin hole.