Pump cant handle extra strain- Vacuum hose?

[sgrrsh26]

Backwashed, hose primed with water from jets, extra skimmer plugged. We've been doing it for years, but this year we are having problems. Whenever we hook the hose up we get minimal suction. at first the pump was losing its prime, after some troubleshooting we can get minimal suction.

The pump works fine on recirculation, and filter without the hose. we notice air bubbles when the hose is connected, but the hose is new without leaks and we tried two separate hoses to be sure. (my initial thought was the hose). Or the pump.. It seems as if the pump is having trouble handling the extra load of the vacuum hose. Any ideas?

 

[sgrrsh26]

Also we noticed the 5 spoke gasket for the Hayward SP-710XR50 is chewed up from the pressure of moving the handle. Dont know if that may be an issue here

 

[Bama Rambler]

The spider gasket could definitely be the problem.
When trying to vacuum does the pump basket have air in it? If so then it could be the basket lid seal. It needs to be cleaned and lubed well.
It would be a good idea to change the spider gasket anyway.

 

[sgrrsh26]

Its strange, why would it only be an issue when the hose is hooked up? I cleaned the basket gasket and lubed it up, there are 2 small bubbles in there, but it isnt an issue when the hose is detached and Im running it through the filter. Once the hose is hooked up it becomes intermittent. The pump primes real nice for about 2 seconds, im getting good suction and then it staggers and looks like its struggling, the water almost bounces in the clear tube, and it repeats this process.

If the hose is attached, this can create a greater opportunity for the basket to leak air?

 

[Bama Rambler]

Hooking up the vac hose increases the suction head and will cause air leaks that didn't exist under less negative pressure. check the pump strainer basket lid and drain plug(s) and the suction plumbing.