Cat pump rebuilt.

I've had my pump rebuilt twice in the past 6 weeks and it's still leaking, the shop is rebuilding it for the 3rd time as I'm typing this, what can cause the leaking to persist with brand new seals every time it's being rebuilt ?
Do I need to raise the flag and buy a new pump if the 3rd time is the charm doesn't work and it's still leaking ?

Are they polishing the plungers prior to installing new seals? If not, there is your problem.

Otherwise, could the pump not be bypassing properly? Is the valve good?

I've rebuilt my Cat 4 times now over the years and still runs strong without leaks. My guess is that you have a bypass issue or else bad rebuilders.

Oh, and are you using the prrrm a lube seals? They seem to hold up the best.

Unfortunately I can't answer any of your questions Rob, lol, regarding the bypass, what bypass are you talking about ?
The first rebuilt I had the plunger seals changed as well as all the oil seals, the 2nd one all the oil seals and the shaft seals, the 3rd one that's being done now they said that they're going to change the oil seals again, not sure what else as they haven't tell me anything as of now. Just hate wasting time waiting around.

Could be a cracked, worn or damaged plunger, or the crankcase is cracked on the oil seal mateing surface.......hopefully Robert is checking those, you might want to ask him, DP.

Heck I'd just have him replace the plungers while he's in there, and inspect the case really well.

Oil seals too failing....I was just thinking pressure seals.

Fatigue crack is possible...you did get down to near freezing this winter didn't you? Long shot, but for consideration.

warped case from over heating,   bad bypass possibly too much heat,   bad plunger warped or scarred from them not being careful with it.    

I know you dont like working on the TM Dp,   but the pump rebuild is a really easy one that I would learn how to do if I were you..   that way you know its done carefully.


oh and last possible cause?    classic mechanic not busy enough in the slower season taking a dump on you..   especially if your having this done at Jon Don,    the jon don here is just a joke for getting your TM worked on I would never ever let them even diagnose my TMs. Theyll keep fixing the pump but they many times wont even look into whats causing the failure, it sucks but its true.. just means more money for them

remember every big manfcter TM has planned ahead of time knowing they dont make enough on the initial sale,   so they rely actually more on you coming back for repairs...     ex employees of their companys have said this for years      

They have projected repair sales as part of the deal,   all lined up with Jon Don so you void warranty if its not done by their sanctioned shops,    they know the TM cost is say 25k with a guaranteed 5k after so many hrs,  and another guaranteed 5k after so many hrs.

What is leaking from the pump? Water or oil? Are the water and oil mixing?

AC speaks the truth...it was the same way in the automotive world.

Well gang, thank you all for the responses, and the biggest thanks goes to Eddy for actually calling me, that's beyond call of duty, lol, so here's the full story, 1st rebuilt is done by my mechanic and he replaced the oil seals and the water seals ( plunger seals ? ), the 2nd rebuilt was replacing the shaft seals and all the oil seals again, the 3rd one today was again the shaft seals and all the oil seals, apparently the o ring was either defective or being installed incorrectly ( Eddie thinks the later ), which I think so too, no cracked head otherwise they will be happy to let me know and charge me for it, lol.
I know I should be learning about all of these myself but I'm not very meticulous when it comes to these kind of stuff and I'm scared of messing things up and made things worse, it's one of my weaknesses that I need to work on
Nonetheless thanks again for all your responses.

You probably could have just bought a new pump with the money you spent on repairs. But then again you probably have beast of a pump to go along with that beats of a TM

Dp, buy yourself a used pump and take your time rebuilding it. You can find them for $150 - $200 and it would give you a spare and a lot of knowledge in the process.

milspec6 wrote:Dp, buy yourself a used pump and take your time rebuilding it.  You can find them for $150 - $200 and it would give you a spare and a lot of knowledge in the process.

That's actually not a bad idea at all, if I can find one used, not much 5cp5140 used out there, worst case scenario I f'd it up and best case scenario I have a working pump to replace the one installed now if it blows in the summer time, thanks Rob.

Mo wrote:You probably could have just bought a new pump with the money you spent on repairs. But then again you probably have beast of a pump to go along with that beats of a TM

Well I spent about $ 500 ( $ 350 labor and $ 150 parts for all the seals including shaft seals and plunger seals which is the most expensive ) and the 3rd rebuilt was the warranty work which is free, now since Robert gave me an idea, I started looking into used cat pump, I noticed that the one in my machine is 5cp3120.aw1 and the one on the Internet is 5cp3120 only, the weight is different between the 2, the aw1 weighs 6 lbs more, I'm just wondering if there's a used one out there, I want to make sure I buy the right one, any advice would be appreciated.

Call Dultmeir and ask them...they are the real experts on these CAT pumps.

Butler uses a special Cat 435, which you can only get from Butler. Dultmeir knew that it was just a 430 with a different manifold to adapt the chemical pump which Butler uses.

I was able to purchase a new 430 and swap the old manifold for almost half the price....everything else is the same.

Give them a call....they are just 45 minutes down the road from me.

I called them and apparently that aw1 is the high heat and higher rpm for gas engine, they have similar model which is 5cp3120.3400, $ 920 ( including shipping ) ouch !!
The aw1 is $ 1100 plus shipping, ouch times 2 !! Lol
If you guys see used ones out there for either model let me know, I'm willing to learn ! Thanks guys !

I sent today watching YouTube vid's about rebuilding cat pumps. Injector chem systems and other fix it stuff. Some people pay 100's of $ to learn this stuff and I got it for free. Now if I DIYS and screw up, then the free wasn't so free.

Hey DP1 did you get your pump fixed or what.

Yes sir, so far so good, I'm still using that machine every day to make sure it's good and no more leaks, I'm still battling the clogging up issues with that machine though, I descaled it the other day and it's still clogging my wands out, white chalky detergents residues.

Is this another example of incompatibility of rinses? Are you mixing different rinses, like say an encap with an acid?

That's the problem I was having, incompatibility....mixing encap with liquid dry slurry was causing serious clogging in the form of "white chalky residues" also. Now since I've switched to straight encap rinse I've had no problems.

I didn't mix anything in my detergents tank, straight dry slurry, half the dilution rate that the manufacturer recommends, mix it properly with hot water gallon by gallon, I have issues with my on / off valve though, it needs to be replaced cause it keeps flowing detergents out even on "off" position.
What's funny is it only happens in this machine, other machines are fine, I'll keep this updated as soon as I figure out what causes this.

dp1 wrote:I didn't mix anything in my detergents tank, straight dry slurry, half the dilution rate that the manufacturer recommends, mix it properly with hot water gallon by gallon, I have issues with my on / off valve though, it needs to be replaced cause it keeps flowing detergents out even on "off" position.
What's funny is it only happens in this machine, other machines are fine, I'll keep this updated as soon as I figure out what causes this.

do you have a last step chemical injection
if you do check the chemical diaphragm

Gerson, the diaphragm was replaced a couple of months ago, what should I watch out for when I check it ?

On friday morning I decided to dump all the detergents in the jug out, I kinda saw some clear sandy residues in the bottom of the jug, but when I dumped them out I didn't see any of those residues, rinsed the jug with clean water and asked my tech to refill with water and see if it's still clogging the wand, they said no it didn't, all day no clogging, hopefully it stays that way.