GHL Maxi - question about replacing tubing inside doser head

[jugsmctugs]

I need to replace the tubing inside the heads of my GHL Maxi. When I insert the new tubing and reseat the rollers, the tubing seems to get squeezed upwards outside of the rollers after a couple rotations of the rollers. Is this normal (i.e., will the tubing stay in place by virtue of the head being reinstalled on the Maxi?) or am I doing something wrong? The manual for the Maxi doesn't seem to address maintenance at all.

 

[Vinny@GHLUSA Verified Sponsor]

When the tube is fully seated onto the head, it will be slightly squeezed between the rollers. That is normal.

 

[lmm1967]

I need to replace the tubing inside the heads of my GHL Maxi. When I insert the new tubing and reseat the rollers, the tubing seems to get squeezed upwards outside of the rollers after a couple rotations of the rollers. Is this normal (i.e., will the tubing stay in place by virtue of the head being reinstalled on the Maxi?) or am I doing something wrong? The manual for the Maxi doesn't seem to address maintenance at all.

GHL had a batch of the tubes that was slightly longer than necessary - if you have one from that batch - it may get pushed outwards like you are describing and get sliced after some time. When that happens - you have yourself a little (hopefully) flood. GHL told me it was due to a combination of the head not snapped on all the way and slightly longer than necessary tubing.

Happened twice to me - had to put a head from an Apex DOS on the Maxi. Both times it happened on heads that had been installed direct from the factory - neither had ever been taken off the Maxi.

 

[jugsmctugs]

When the tube is fully seated onto the head, it will be slightly squeezed between the rollers. That is normal.

Thanks, Vinny -- just to clarify, if I manually rotate the rollers, part of the tubing always ends up being pushed upwards such that it is no longer being squeezed between the rollers and the housing of the head. I attached four photos to show what I'm talking about. The first two photos show how tube looks after replacement and second two photos show what happens to the tube after manually rotating the rollers (maybe one-half to one rotation). I want to confirm whether that's normal and the tubing will stay in place once the head is reattached to the doser or if I just didn't properly install the tubing/re-seat the rollers.

 

[Member No 1]

Before I started to use mine, I was sent this. You might want to check the length.

During our regular quality control checks we found some maxi tubes that were slightly longer than they should be.
The correct length for this tube is 145mm or 5.7 inches with a tolerance of (+/- 1mm or .04 inches)

Our tests show that if this tube is too long, it may shift or move out of the correct position in the head. If this happens, the tube could get damaged after extended run-times, especially if the pump head is not perfectly snapped in.

Once I corrected the length, It's been doing (2) 1.5gal AWC per day with out any issues. It's been running since the end of May.

 

[jugsmctugs]

GHL had a batch of the tubes that was slightly longer than necessary - if you have one from that batch - it may get pushed outwards like you are describing and get sliced after some time. When that happens - you have yourself a little (hopefully) flood. GHL told me it was due to a combination of the head not snapped on all the way and slightly longer than necessary tubing.

Happened twice to me - had to put a head from an Apex DOS on the Maxi. Both times it happened on heads that had been installed direct from the factory - neither had ever been taken off the Maxi.

That is exactly how the tubing in one of my maxi heads split (luckily it was on the bottom of the hardware stack consisting of my P4, 2.1 Doser and Maxi). It was the original factory-installed tubing and only had ~2 months usage as AWC. Hopefully the replacement tubes I bought from GHL are correctly sized . Didn't realize the DOS and Maxi heads were interchangeable.. good to know.

 

[jugsmctugs]

Before I started to use mine, I was sent this. You might want to check the length.

During our regular quality control checks we found some maxi tubes that were slightly longer than they should be.
The correct length for this tube is 145mm or 5.7 inches with a tolerance of (+/- 1mm or .04 inches)

Our tests show that if this tube is too long, it may shift or move out of the correct position in the head. If this happens, the tube could get damaged after extended run-times, especially if the pump head is not perfectly snapped in.

Once I corrected the length, It's been doing (2) 1.5gal AWC per day with out any issues. It's been running since the end of May.

Thanks for the measurements! Will measure the existing and replacement tubes when I get a chance to see if that was/is the problem.