I have poured a few drill shafts the past few days and had to reduce to 4" line in the hole.. We usually choke up sometime during the pour, which never makes anyone proud, but whats the proper way to pump these things?? There has to be a trick to it...

It is interesting how we take a name of a thing from those around us. Drill shaft is an apt name. When I was in Den,CO they called them caisons; your name is more correct I think.

Are you using a boom?

Is the reducer right at the tip elbow?

Is the end of the (hose or pipe) in the concrete?

Are you displacing water?

I bet that there are lots of folks that have made this exact pour. We/I need some more info... please. ;~)

what is  it your having a problem with I pump these alot with boom pump

Here is a copy of an email that I received.

Bob if you or members have questions on pumping caisons and columns please feel free to call me I am no expert but pump for drilling  or I should say I am  employed by them and my jobs is pumping for them my# is 760 455 9495 24/7 going home for holiday today so no putr till next week call if you like john daniels happy turkey day

I have done thousands of shafts up to 100' depths.Anytime you reduce theres a chance for blockages.The best way i have found is to use 5" when possible.If you cannot the blockages are just gonna be part of it.If you are waiting a long time try recirculating might help.Try not to put pipe in the mud at bottom.In the past I would break off trimee to recirculate wash reducer and pipe and hook it back up when they where ready to pump again.GOOD LUCK. 

  These shafts were only 20' deep, and yes we were displacing water.. I would reduce at the tip then go from 4" flex hose to the 30' of steel pipe we had in the the hole.. We had to use plenty steel pipe because of the rebar sticking up out of the hole.. The mud though varied through the pours, one truck would be really wet, then the next may be really dry.. That may have been some of the problem, but I could'nt tell ya, this was the first time I have ever filled these..  I'm sure 5" line would have benefited alot, but I had to work with what I had.. I just hope I did'nt screw up the pours for this company, I don't really see how you can go wrong even with the problems we had, but I guess you never know till they test it..

As to your problem: I think it was just some bad crete.

As to your procedure: WAY TOO MUCH GEAR = WAY TOO MUCH WEIGHT

I am glad that you do not have the 5" gear.

Seriously out of compliance & not conducive of long boom life.

Do not ever tell anyone who you are... lawyers have long memories.

  Bob, I had a crane holding all my gear, don't worry about that.. I was very leary about the weight also and told the guys I would'nt even pour it unless there was a crane there to hold all my line and they did have a crane on site.. I DO NOT need to bend my girl up one bit, that truck is my pride and Joy..