Generic question re greasing pressure relief valve

PeterJones

Active Member
Joined
Jan 3, 2017
Threads
11
Messages
58
  • / Generic question re greasing pressure relief valve
Hi,

I have recently replaced all three cutter blade spindles on my scag cheetah. I have installed the new spindles and, unfortunately, decided to grease them post installation.

My problem is that two of the grease pressure relief valves are not working (stuck I suppose). When I grease the excess grease comes back out of the grease nipple.

My question is just how big a deal is this? Must I remove the spindles and fix the problem or does the fact that the grease is coming back out around the grease nipple give me confidence I'm not over greasing?

TIA, Peter
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
79
Messages
10,273
  • / Generic question re greasing pressure relief valve
You two different comments here. So which is it? Is coming the check valve or is coming around the outside edge?

If the grease is leaking back out the grease zerk center then it is defective as they have a spring loaded check valve that suppose to prevent this. Personally I would replace them if that is the case. The problem that might arise is if they are pressed in versions. If so then the mounting hole must be tap to accept the threaded version.

If leaking from the outside edge then they are not sealed there from an improper fit.

Others will have their own opinion on this. I just know an one way check valve is defective when it fails to seal off in the reverse direction, just one that fails to allow flow in the forward direction.

Now I can't answer if you are under or over greasing as I am not there to see for myself. As said others will have their own opinion on this.
 

PeterJones

Active Member
Joined
Jan 3, 2017
Threads
11
Messages
58
  • / Generic question re greasing pressure relief valve
Thanks ST,

I can't see if the grease is coming from the zerk centre as the only thing I can report is the grease seems to flowing from all around the the grease gun nozzle. i presume this is because it is leaking back around the outside edge of the zerk. I actually didn't see this as a problem as I've seen this behaviour with multiple grease nipples on different equipment over the years and I simply thought it was 'normal', i.e. if there was no specific pressure relief valve this is what happens when the cavity is full.

So, yes, I do seem to have two problems - bugger!!

Cheers, Peter
 

Hammermechanicman

Lawn Addict
Joined
Jan 10, 2020
Threads
56
Messages
3,528
  • / Generic question re greasing pressure relief valve
If grease is coming out between the coupler and the zerk it sounds like they are not compatible. I have 3 grease guns with different couplers just for that reason. Not all zerks are the same. I have tried a few "universal" couplers and they don't fit everything.
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
79
Messages
10,273
  • / Generic question re greasing pressure relief valve
If grease is coming out between the coupler and the zerk it sounds like they are not compatible. I have 3 grease guns with different couplers just for that reason. Not all zerks are the same. I have tried a few "universal" couplers and they don't fit everything.
That is something I assorted forget about but I also ran into that problem a lot last year. It cause by manufactures not adhering to specs. That what we get with so many crappy Chinese companies dumping products on us. Even with the manual locking lever action coupler that I installed last year I have problems so I got second coupler. It hangs after going on and I have to manually unscrew the shell so the jaws can unlock. I had to change out multiple zerks that either coupler would not simply stay attached.

This not adhering to specs is only getting worst during the current business climate. And as said before many Ebay and Amazon vendors are a large part of problem as they simply sell junk. Personally here I have nearly quit ordering parts from either of them ; unless, I know that company I dealing with is a reliable company. It is a shame that these flyby night companies are allowed to stay in business. Some are so bad they only exist for a month and then close down and change their name then do it all over again.

Even my machine shop supplier McMasters-Carr recently sent me a riveter that was spec to fit 3/16 316 stainless rivets that I was installing. The nose piece would not even accept the mandrels. I was lucky that I done ran into this problem with one from HFT so I had ordered a second nose piece so I could modify it but I got lucky as the second nose piece was to spec.

Then there is my recent experience with MTD parts where I ordered brake pads. They were so crappy that I had to return them for credit as they were $90.60 for 12 of them. Now it looks like I will have make them in house using stock brake liner material. The problem is that I need to get a mill bit to do the countersink holes but at least the ones I make looks a lot better.

Here is what those MTD pads look like that my MTD distributor sent me. They look better in the image than they did in hand. They were not as thick as the original pads either.
1641559681756.png
This is what they should have looked like.
1641559946200.png
 

Hammermechanicman

Lawn Addict
Joined
Jan 10, 2020
Threads
56
Messages
3,528
  • / Generic question re greasing pressure relief valve
I have received a couple of OEM MTD belts made in India. They worked OK older ones said made in USA. I think the manufacturers are racing to see who can built the cheapest $1500 mower as that seems to be the going rate for the cheapest box store mower. At least they have pretty decals on them even if the steering gear and decks are junk.
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
79
Messages
10,273
  • / Generic question re greasing pressure relief valve
I sure hope MTD had a better quality control over the India made belts than A&I.

And now that MTD has sold out no telling what junk we are going to be dealing with. Boy I am glad I only have to do this work for a living for another 2-1/2 years.

To me it looks most corporations has gone from caring about long term business to just now business without caring about future sales.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,705
  • / Generic question re greasing pressure relief valve
Thanks ST,

I can't see if the grease is coming from the zerk centre as the only thing I can report is the grease seems to flowing from all around the the grease gun nozzle. i presume this is because it is leaking back around the outside edge of the zerk. I actually didn't see this as a problem as I've seen this behaviour with multiple grease nipples on different equipment over the years and I simply thought it was 'normal', i.e. if there was no specific pressure relief valve this is what happens when the cavity is full.

So, yes, I do seem to have two problems - bugger!!

Cheers, Peter
You could also have a rusted closed nipple
I regularly have to remove a nipple, put it in my very high pressure McNaught gun and pump some grease through it.
I do the same with all the new ones I fit to make sure they are working properly before they go in.
The assortment I got from Stens has about a 10% failure rate.
The ones from McNaught are a lot better but 10 times the price.
I got caught with a clogged nipple that ended up being a ball bearing from a failed bearing stuck in the grease hole that the DPO failed to remove when he replaced the spindle bearings.

Got a 44 series B & S in there at the moment that the owner "does better than required maintenance " on .
Premium long life B & S oil filters changed every year.
Blown a head gasket & cooked both heads because the blower housing has never been off in 11 years .
I had to wet sand blast the engine to get it clean enough to strip down .
 

hlw49

Lawn Addict
Joined
Jul 11, 2021
Threads
36
Messages
1,392
  • / Generic question re greasing pressure relief valve
The best grease gun couplers I have ever used are the De Walt. They stay on the fitting better and last a lot longer than the generic ones.
 

PeterJones

Active Member
Joined
Jan 3, 2017
Threads
11
Messages
58
  • / Generic question re greasing pressure relief valve
Wow, I had no idea grease nipples were such a potential cause of problems. I had the opportunity to grease the spindles before installing them - now I have remove them!!

Never again, always check parts grease up as advertised before installation.

Cheers, Peter
 
Top