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3CX 1989 Hammer circuit

Cristian

Member
Joined
Jul 16, 2017
Messages
10
Location
Croatia
Hello. I have a question about how to add hammer circuit on my 1989 3cx. For the pipes along the arm there is no problem. The only problem is the valves. Someone is advised to install a priority valve with electrical control, others say they install a system more similar to the original (diverter and valve in sequence). What do you recommend me?
 

jcb jeff

Senior Member
Joined
Nov 23, 2014
Messages
394
Location
United Kingdom
A cheap way of doing this is to run a return line back to the hydraulic tank 1" bsp free flow no restriction .Then on the dipper ram on the head side of the ram the one nearest the cab put a t piece in the hyd line with a quick release coupling in and connect breaker there so when you use the breaker you will just use the dipper service so pull dipper into the machine which it will keep weight on the breaker and as the ram cant go anymore it will fire the breaker up.
 

Cristian

Member
Joined
Jul 16, 2017
Messages
10
Location
Croatia
Thanks jcb Jeff. I would like to do it a bit more professional. I have a priority valve, but some say that it overheats the oil so much, for the system as original I should take diverter and sequence valve. I saw on hydraulic diagrams before the place of the valve sequence there was a non-return valve. What is the task of this sequence valve in addition to opening the oil passage after reaching the 21bar. I see he also has a drain line
 

Cristian

Member
Joined
Jul 16, 2017
Messages
10
Location
Croatia
3CX-4/344947/P. I have standard boom, auxiliary circuit (foot) and dont have hydraulic oil cooler. thank you jeff
 

Cristian

Member
Joined
Jul 16, 2017
Messages
10
Location
Croatia
Thank you !!!! I had already seen an identical pattern, only I was told that they had never seen a similar circuit on 3cx. Now I have the confirmation that you can install it. Do you think, if I have in future problems with overheating of hydraulic oil? The priority valve I have to put in is 3/4" max flow 200l/min (44gpm), leakage max 3l/min (0.65gpm). The pump is double with max flow 100l/min (22gpm). The hammer to install has a flow of 30-70l/min (6.6-15.4gpm). Thank you again!
 

jcb jeff

Senior Member
Joined
Nov 23, 2014
Messages
394
Location
United Kingdom
If you have no oil cooler then things are going to get hot very quick running a hammer from this machine.
Do you have extra dig circuit ?
 

Cristian

Member
Joined
Jul 16, 2017
Messages
10
Location
Croatia
Yes i have foot pedal auxiliary circuit (for extradig-not fitted, jaw bucket 2x1/2 hose). The pump is P1 63l/min and P2 37l/min.
 

jcb jeff

Senior Member
Joined
Nov 23, 2014
Messages
394
Location
United Kingdom
From memory on the later machines that p1 flow goes through front loader valve then on to the rear valve block on the high pressure carry over line,when the oil leaves the rear valve block it needs to go through the divert valve and then onto the sequence valve which combines the flow from the p2 and p1 to give a combined flow then the returning oil goes back free flow to tank .
 

Cristian

Member
Joined
Jul 16, 2017
Messages
10
Location
Croatia
Hello Jeff, you would know if there is still a hammer kit with tubes and valves available for this machine 3CX-4/344947/P, or for the next model 400000-430000 is almost identical. I can not find anything on the web, I only find single parts. Thank you!
 
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