When installing piston with new o rings and cup washer . There is a tool to put the piston back in master cyl. .. is there a way of getting piston in with out special tool?
has anybopdy improvised anything? let me know
1993 polaris 350L

 

I have a 1990 Trail Boss (W908139). I have been searching and searching for the same answer the previous post asked above. Not one response to him after 5 & 1/2 yrs. In Lieu of starting a new thread, I'll just bump this one to see if anyone has the answer.

I am in search of this "special tool" that is required in order to install the piston back into the master cylinder of a 1990 Trail Boss 350L (W908139) {several other models & years as well}. There is absolutely no way to get the beveled seal into the cylinder without some sort of tool to prevent the lip of the seal from folding. Here's some part numbers of the piston and seals I'm putting together and a link to one of many places I get parts.

Piston: 502052
U Packing Seal: 5410164

Cheap Cycle Parts

The seal is directional and putting it in the other way around makes for an easy piston install, but will not give sufficient pressure for braking. I did that earlier this week just for the hell of it. I rescued this quad from rotting away in someone's back yard over a year ago. The brakes are the final piece to fix. This and this alone is my final hurdle so I can ride it without killing myself.....lol. I have been riding it off/on with no brakes since I got it running. I've called a couple Polaris shops who said they would "get back with me" about this special tool and so far, none of called back (2 weeks ago).

Thanks guys/gals.

In the mean time, I'm going to continue some creative ways to try and make the seal/piston get back in the cylinder.

 

Hard to find this little tool used on the early Polaris master cylinders. All it actually was was a small steel sleeve milled on one end. The piston and cup seal was pushed in from the beveled end,then this end inserted into the master cylinder cavity.Then you could push the piston and seal in with out damage to the cup seal.Doesn't even show this little tool any more and don't know if these would even work on the early models.https://polaris.service-solutions.co...7&cat=1&sub=27 But if you're careful and have a small flat screw driver to work the edges of the seal in,you might be able to do it without damage. Check the bore of the master cylinder carefully. If it's corroded,might as well replace the old red handle master cylinder with the updated master cylinder assembly that's a heck of a lot better,but a little pricy. Item #36.Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse

 

Awesome!!! This is the "mystery tool" I keep reading about on this and other forums. I've never needed a special tool for any master cylinder rebuilds, so it was new to me. I've attempted several ways to install without the tool, but due to how far recessed the seal is into the Master Cylinder, it's dang near impossible to get anything in there to try and work the seal lip in slowly.

Thanks again for the info.

 

Finally found it. 2870962-B. Shows here on dealer only page for SPX tools and also the old Kent Moore/Spx tools pdf. https://polaris.service-solutions.co...x?id=185&cat=3
http://gh-ftp.com/ORV%20Manuals/Pola...AL%20TOOLS.PDF

 

That manual is perfect. I'm going to give the company a call tomorrow asking about ordering the tool. Not sure why it is only available to someone with a dealer # and LLC #. I'm hoping they will sell it to me or I will have to utilize a business to order it for on my behalf. I'll update all when I know more tomorrow.

 

Or if you have a local dealer just let them order it for you. We ordered quite a few special tools for customers that wanted to work on their own machines.

 

Yeah, I was going to try that route today and stopped by 3 different places after work. It appears for my area, Monday is the new Sunday. seriously, every dang shop was closed on Mondays WTH?!?!?! I'm going to try again tomorrow. I also am carrying the Master Cylinder with me and hope that maybe one of the shops will take 5 seconds to just pop the piston into the cylinder on the spot. We shall see.

 

Most shops are closed on Mondays as they're usually open 6 days a week and late on Saturdays same as we were. Even mechanics need a break.

 

Yeah, that is true. An update to close this thread out. Got a hold of the guy @ RV Service Tools and he had no issues selling me the tool. Here's the link: RV Service Tools
I should have it in my hands in 2-3 days pending any delays with all the winter weather along the East coast. About $30 with shipping costs, but hey, that's a lot cheaper than $150 for a new MC. A guy on another ATV forum provided this avenue to source out the tool.