Hitachi does the doo-dah

[bankruatsteve]

I know this has been discussed in this forum previously but a search for "bladder" comes up zero.  Strange.

 

My Hitachi 250GX2 started doing the doo-dah (like da-da-dahhhh) briefly every 10 minutes or so about one month ago.  I unscrewed the bladder and it was full of water.  Let it drain and screwed back on.  There is no place to inject air.  All good until a few days ago and the doo-dah starts up again.  Unscrewed, drained, and seems OK again.

 

If I recall, the bladder is not supposed to be water logged, right?  And, if it is and keeps happening, it should be replaced?  Or, is there a fix?  Or, just do the draining until I get-round-to getting a replacement (does it hurt the pump)?

 

Thanks

[VocalNeal]

There will always be a little bit of water in the accumulator as the gas inside is compressible but it should not be full. You can check the gas fill sort of by poking a ,say, wooden spoon into the thing and seeing if you can get a balloon like feel. 

 

Probably simplest to replace. Although,I believe,  some have managed to fit a car or bike valve and re-pressurize 

Edited April 22, 2020 by VocalNeal

[bankruatsteve]

I guess replace is the only option as there is no fitting to re-inflate.  Is there potential damage to the pump in that condition?  

 

B1100 in Lazada.  Seems strange the bladder should be almost 20% the cost of a new pump.  It just went past the 5 year warranty of course.

Edited April 22, 2020 by bankruatsteve

[VocalNeal]

There is a minuscule duty cycle increase but nothing that would worry me short term. 

 

A note: Replacing the tank may not solve your problem but it will eliminate one possibility. 

 

Q. Has anything else changed? Any plumbing work or addition been done?

[bankruatsteve]

No problem otherwise.  When I drain, it's OK for a while - until it water logs again, I suppose.

[Sophon]

If you want something a little cheaper than the original Nitrogen accumulator, you could try replacing it with one of the inflatable types like this https://www.lazada.co.th/products/1-2l-i289848068-s480320807.html?

[bankruatsteve]

Thanks for that.  I assume they have a common fitting.  I also found the Hitachi for B900.  And, I now remember I have an old pump that needed replace when the mounting bolts corroded and couldn't be tapped out.  Maybe give the old bladder a try first.  

 

Cheers

 

[Fruit Trader]

3 hours ago, bankruatsteve said:

If I recall, the bladder is not supposed to be water logged, right? 

There will be water on the pump side of a bladder tank.

 

Bladder tanks are charged to a pressure around the cut in pressure of the pump to function correctly.

 

A simple quick test for the small bladder tanks on compact house pumps is to measure how much water can be drawn off before the pump cuts in.

 

If you replace the bladder tank be sure it is the correct charge pressure for the pump. Bladder tanks with charge valve can be adjusted using a car tire pump.

 

[Metropolitian]

Something like this ?

 

    

I just stumble on that product while looking for a tank. And remembered this thread.

It is here

 

[Fruit Trader]

17 hours ago, Metropolitian said:

Something like this ?

 

     

 

 

 

Should be a little more adventurous now he has the shirt.

 

[bankruatsteve]

Score 1 for saving stuff "just in case".  The old accumulator fit and after 2 days no doo-dah.

 

Thanks for all the replies.  Cheers.