Maxxforce egr cooler info

Well I know this topic has been beat to death but I have my first maxxforce egr cooler repair coming up and have a few questions. I am a municipal mechanic with a fleet of 14 tandem plough trucks and all but 5 are Workstars with maxxforce 13. We buy extended warranties but a few of the older units are off warranty. The unit I have is having low egr flow codes. I removed the front cover off the front of the low temp egr cooler and found it very plugged and evidence of coolant contaimination which is as I have learned is most likely a sign the high temp cooler has failed.

1. I know the high temp cooler core is removed through the back using a puller but I am wondering how the low temp core is removed is it removed using a puller aswell and if so is it the same puller as used on the high temp or a different one? Does not look to have enough room to use a puller at front of cooler. Or is the low temp cooler housing sepperated from the high temp cooler and core removed after it is removed from engine? I am also aware there is a alignment tool required if the housings are sepperated.

2. Since the low temp cooler is plugged, and high temp cooler is most likely leaking is it more cost effective to buy a complete new cooler with cores and housing already assembled or replace both high and low cores into existing housing?

3. while I am repairing cooler should egr valve be replaced while doghouse is removed and everything disassembled or if no egr valve faults leave it be?

Not even sure if it is worth while for me to do the job as opposed to send to dealer as we have a 2011 11lt, and 2 2012 13lt and all the rest are 2015 and newer maxxforces with scr so debating if 3 units is worth the egr tooling? I just don't like sending to many jobs out.
I have seen quite a few vids on high temp core removal but not much info on low temp side core removal.
Any info provided is appreciated

 

Thanks kubasj05 As far as the rear puller goes my boss was talking to our IH dealer about this and they told him that they have a used puller that they are willing to give us. It is slightly bent but they figure it can easily be repaired. Being a dealer they just wont risk it and ordered a new puller. The parts will be coming from the dealer so as much as I would like to use the m1m cooler I suspect they will supply oem cooler but I will inquire.