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Keep blowing seal in piston..how to prevent?

5.9K views 33 replies 20 participants last post by  BrownAzt3ka  
#1 ·
OK this is really starting to piss me off anf cost me money (in motors :angry: )
Prohopper piston...90 Lincoln towncar.....
Never had more than 100 pounds of pressure and have blown through every shaft seal I have tried.
"Blow proofs".....nope....gone through two of them. The other blowproofs...the aluminum ones with the two inner o-rings and the two outters....just went through one yesterday. I am at a losss here........any one have any suggestions?
 
#3 ·
how does the block look head seal ect... post pics
 
#4 ·
run less pressure i heard the ph pistons worked ata lower pressure failing that buy a real piston from bm
 
#6 ·
Originally posted by NY-BOSSMAN@May 19 2008, 10:18 AM~10686656
how many blts are holdin the head on ,maybe the head aint seatin tightly against the block for some reason
that would blow the pressure seal not the shaft seal
 
#7 ·
take the pumphead out. get a new shaft seal, clean the block using brake clean especially where the shaft seal seats itself to the block. then using silicone, put it in the groove where the seal will seat itself into the block, then put your pumphead back on and let it sit for a few hours if not over night to make sure the silicone dries and doesnt get any oil on it.. we have had the same issue before with a set of black magic piston pumps generation 1.
 
#8 ·
i would also make sure that ur pumphead is bolt down correctly using the criss cross pattern and that they are torque down to the specs if ur not sure about ur hand tighning skills of the pumphead. even if u use all 4 bolt and it becomes loose it can still walk itself off the shaft and allow fluid to pass by the shaft into ur motor.
 
#10 ·
Originally posted by timdog57@May 19 2008, 02:42 PM~10687262
Thats BS seen one hold 600 psi with my own eyes.  Also saw one that had like 900 psi and it blew apart.  :0
:0 we need pics,cuz you tend to tell untruthes ;)
 
#13 ·
Originally posted by timdog57@May 19 2008, 12:42 PM~10687262
Thats BS seen one hold 600 psi with my own eyes.  Also saw one that had like 900 psi and it blew apart.  :0
finally the truth...it not your piston im pretty sure if u hammered a seal in the aluminum block it may be bigger that it should i would look at block...i put seal in block first that install gear...i tap them in w a rubber mallet and have had no problems i never use the stock steel seals lots of problems... :cool:
 
#16 ·
Originally posted by 41chev@May 19 2008, 01:45 PM~10687706
i know the problem  :biggrin: its the seal .............. it just needs a new pump  ;)
Your funny.... I think with all what he is saying I do think the block is junk... I've some of the steel ones leak in 2 places... first was from pressure port to key hole.Block had failed
2nd was motor bolt landed in one of the pump bolt hole and bleed there.

Also just seen a 1'' with the motor bolt land into the pressure port.


Get a new block if any of these are the cause ;)
 
#17 ·
Originally posted by BlackMagicHydraulics@May 22 2008, 03:16 AM~10710629
.

Also just seen a 1'' with the motor bolt land into the pressure port.
Get a new block if any of these are the cause ;)
that's me :biggrin: it's actually the pumphead bolt to the pressure port.

Image
 
#18 ·
Originally posted by Roma@May 19 2008, 09:51 AM~10685669
OK this is really starting to piss me off anf cost me money (in motors  :angry: )
  Prohopper piston...90 Lincoln towncar.....
Never had more than 100 pounds of pressure and have blown through every shaft seal I have tried.
"Blow proofs".....nope....gone through two of them. The other blowproofs...the aluminum ones with the two inner o-rings and the two outters....just went through one yesterday. I am at a losss here........any one have any suggestions?
not sure, but it could be the block, had the same problems with another pump few years ago, kept blowing seals and burning up motors. after months of blowing money, i found out that the block itself was machined wrong, couldn't tell by eye, but the pumphead bolt mounts was off by .010 and it would blow that seal all the time, tried the steel seals too with no luck.. after i changed the block, no problems..
 
#19 ·
I will take a few pics tonight........got the pump tore down and discovered something pretty interesting.
The shaft seal.. (aluminum double exterior o-ring type)....was actually bent up on on side just a fraction but it allowed the second o ring at the outside base of the seal to bust through.
So who knows...I have never seen this happen before....... :confused:
 
G
#20 ·
Originally posted by Roma@May 23 2008, 01:49 PM~10721282
I will take a few pics tonight........got the pump tore down and discovered something pretty interesting.
The shaft seal.. (aluminum double exterior o-ring type)....was actually bent up on on side just a fraction but it allowed the second o ring at the outside base of the seal to bust through.
So who knows...I have never seen this happen before....... :confused:
HIT ME UP LATER :cool:
 
#21 ·
Originally posted by KINGFISH_CUSTOMS@May 19 2008, 11:30 AM~10687194
i would also make sure that ur pumphead is bolt down correctly using the criss cross pattern and that they are torque down to the specs if ur not sure about ur hand tighning skills of the pumphead.  even if u use all 4 bolt and it becomes loose it can still walk itself off the shaft and allow fluid to pass by the shaft into ur motor.
:thumbsup: I personally don't like to use sealant. But you for sure need to make sure the block and gear are super clean and torqued properly. I also go the extra mile and rub a honeing stone over the block surface to make sure it is perfectly flat and sometimes on the gear too if it has been used. Just to make sure there are no burrs that can cause the head not to seat properly.