Blow down blowing back up into presoak tank.

[Diana]

Our blow down seems to be intermittently coming back and blowing up into our presoak tank and bubbling it up and cutting the volume of presoak product that makes it to the car. Where should I start? Looks like there are 8 check valves and a pump between the presoak supply tank and the hoses leaving the equipment room. Is there a way to check the check valves without replacing all of them? Since this is an occasional problem, (happening more and more lately) this could be very time consuming to replace one check valve at a time and observe. Thought maybe some of you old timers might have a suggestion, maybe there is something else I should be checking?

 

[Waxman]

Our blow down seems to be intermittently coming back and blowing up into our presoak tank and bubbling it up and cutting the volume of presoak product that makes it to the car. Where should I start? Looks like there are 8 check valves and a pump between the presoak supply tank and the hoses leaving the equipment room. Is there a way to check the check valves without replacing all of them? Since this is an occasional problem, (happening more and more lately) this could be very time consuming to replace one check valve at a time and observe. Thought maybe some of you old timers might have a suggestion, maybe there is something else I should be checking?

My thoughts are: are nozzles restricted? if so fix. Is there a pressure regulator for blowdown air? If so you could turn blowdown pressure down a bit.

8 check valves seem like alot. Check valves can fail, though so you may look at those too.

 

[I.B. Washincars]

Here's an idea, but I don't know if it's feasible. It definitely sounds like a CV issue. Can you clamp off each hose, one at a time, with a pair of vise-grips or something? I would think that the one with the offending check valve would pop. IIRC you have a D&S machine, which I am not familiar with at all, so my suggestion may not hold water at all.

 

[borumrm]

Our blow down seems to be intermittently coming back and blowing up into our presoak tank and bubbling it up and cutting the volume of presoak product that makes it to the car. Where should I start? Looks like there are 8 check valves and a pump between the presoak supply tank and the hoses leaving the equipment room. Is there a way to check the check valves without replacing all of them? Since this is an occasional problem, (happening more and more lately) this could be very time consuming to replace one check valve at a time and observe. Thought maybe some of you old timers might have a suggestion, maybe there is something else I should be checking?

If you have the D&S then there really should only be two check valves that might be the culprit if you set up is like mine. Follow the hose from the presoak pump up the wall to where the manifolds and check valves are located. At some point they will tee off with a feed going to two different check valves (on second thought there might be three...we don't put presoak out all eight of the top nozzles only one side of four) ... anyway those would be the check valves to check. It sounds like one of them is sticking from time to time but only with low pressue....if it fails or sticks open with high pressure usually one of the hoses will rupture.