My Experience Using A Seal Mate

After starting the bike for the first time in three years, the next day I took a thirty mile ride. Several hours later I noticed my front forks were leaking. The right one was leaking a bit, enough to drip down onto the tire. The left one was more severe, leaving a puddle about the size of three or four quarters by the next day.

I fully intend to overhaul the front forks, change to progressive springs, fresh oil… but I really didn't want to have to do it right away. I have a long list of more critical work to get done. I saw mention of the Seal Mate, watched a couple videos, and ordered one immediately. If this thing could fix the leaks even for a while, it'd be well worth it.

The first question is, why pay $7 for something people improvise out of old milk jugs? My answer is… yes I could make a tool, and it might work well. But for me, seven dollars is not much to pay for a proven solution. It may be a simple piece of plastic, but it's made in a size, thickness, flexibility, and shape that is proven to work with near universal positive reviews. I'd rather work with a known good tool my first time than experiment. If it didn't work, I couldn't be sure if the improvised tool or my technique was the problem. Now that I've done it and see how it all works, I'd be more willing to improvise in the future.

There are many videos on YouTube showing how it works, such as this one:

They're helpful to get an idea of how it works, but my experience was much different!

What you read in reviews and see in videos is that sure, a little oil might leak out as you insert the tool past the seal. Then as instructed, they circle the tool completely around the fork 1-2 times before withdrawing it. This was not my experience at all.

The instant the tool went past the seal, a LOT of oil immediately started to leak down the fork, covering the tool and my hand. I mean, instant and complete mess of fork oil. This made it absolutely impossible to keep a firm grip on the tool and move it completely around the fork in one pass. Also, I couldn't leave it inserted while I tried to reposition for a better grip, as oil continued to pour out.

So, here's what I had to do…

Very quickly, insert the tool, scrape it around the seal an inch or a little more, and withdraw it. Wipe off the tool, my hand, and the fork, then repeat again a little further around the fork, overlapping with the last pass. I ended up making overlapping passes a total of twice around each seal.

The oil leaking out could actually have helped, as it might've flushed out any dirt that the tool scraped loose. And I say it leaked a lot, but I don't believe enough to compromise the proper level of oil in the forks, just enough to make a mess of the process.

Other notes:

The Seal Mate instructions say to clean around the seal with a rag and contact cleaner. I used CRC QD Electronic Cleaner throughout this process, and it did a really nice job. The point is to have something that can flush dirt and grease without harming the rubber seal.

I had to pump the forks a lot to get the seals to fully reseat. I'd do a set of 12 aggressive presses on the handlebars, check for residue on the fork, wipe clean, and repeat. It took about 15 rounds until it was seated, and I wasn't completely confident it was perfect. But after riding it more and giving it a couple days to sit, I can confirm there is absolutely no leak on either fork now. And yes, I had misgivings about the neighbors seeing me aggressively humping the bike to reseat the seals. But the results were worth it!

Bottom line: it worked. Just be prepared to deal with a mess and improvise the process.

Good write up - that's exactly how i did mine and the same oil pissing out but I managed to get all the way around in one pass.

Good write up...but I wouldn't discount the lost oil - If 2 tablespoons came out then you've lost about 5%. That's same as half a pint of engine oil.

mr hunt said:

Good write up...but I wouldn't discount the lost oil - If 2 tablespoons came out then you've lost about 5%. That's same as half a pint of engine oil.

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How does one check the oil level?

I would not discount the oil loss . After the sizeable leak you mentioned , as well as the oil loss whilst using the seal mate . How do you know there is actually any oil left in the forks ? There is only around 600cc in each leg to start with , which isn't a huge amount !
Running with too little oil would quite possibly destroy the dampers and make riding a very dangerous affair ! Rebuilding the forks is only an hour or so work , with another 2 to 3 hours removing and refitting them if you take your time . You would have to remove the forks anyway to check the oil level and air gap . So for safety sake and piece of mind , spend a morning , do the job right and do it once . A small price to pay for safety !

Mittzy said:

How does one check the oil level?

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Sadly what Nat said ^^

Oh wow wow wow, seriously impressed with this site, once again. The last month or so I noticed an oil leak on my RHS fork. Read this thread and watched the video and learned a bit on why it might be leaking, possibly dirt and not simply worn. I didn't have one of those seal mates but I thought I would try that idea with my .229mm feeler gauge. I only managed to get access to the outside edge but that was where the leak was from. Only minimal oil loss. I bounced the bike up and down 8 times in 3 lots wiping the fork each time, last time it is clean as. Appears the leak has been sorted. Very happy ☺

There was an earlier post about changing the oil weight. Can anybody recall this?

mr hunt said:

That's same as half a pint of engine oil.

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I get your point that it's an amount worth noting and probably worth taking action. For what it's worth, I wouldn't worry about being a half pint down in engine oil, as long as it wasn't an ongoing leak. In my experience that's half the level between min & max on the dipstick… worth topping up, but not really a problem, particularly with a dry sump design.

Nat67 said:

So for safety sake and piece of mind , spend a morning , do the job right and do it once . A small price to pay for safety !

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I really do agree with your conclusion. I know there's still oil in the forks because I can insert the tool and still get a strong leak. But I also have no honest idea what the actual level is. And even in the best case scenario, I'm sure it's outside the +/- 4mL spec.

I regret my phrasing regarding the amount of oil loss and not being concerned. I wouldn't want to imply what other people should be concerned about, or discourage anyone from taking the time to do it right. I only meant to communicate that I am not personally concerned with it right now, given the condition of my bike overall, my goals, and the small amount of riding I'm doing.

I don't love saying so, but even though my bike is running and rideable right now, it's still in extremely rough shape. Safety is compromised in multiple ways, and I'm really doing little more than careful test rides between working on it. I would never take it on a trip or push it very hard in its current condition.

So as I did mention (maybe this gives it more context), yes I fully intend on doing the job right very soon, I just wanted to stop the leak at least temporarily to buy me some time while I work down the list of jobs to do, which includes other (more serious) safety and mechanical concerns.

So definitely, I will get to it, and fairly soon. And I want to be clear, I encourage anyone else with a similar fork leak to also take the time to do the job right as well. But I also believe there is a place for the quick, temporary fix of at least stopping the leak.

Mittzy said:

There was an earlier post about changing the oil weight. Can anybody recall this?

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In my research after noticing the leaks, I read every post I could find about fork rebuilds and spring replacement. There are many posts discussing oil weight. I don't recall one thread standing out in particular. The gist of what I got was stock oil is 5-weight, and there could be benefits (particularly if you're heavy or ride two up a lot?) to increasing that as high as 10, with 7.5 being popular.

The idea is it's the oil movement that controls the amount of dampening. To change it, your only options are to change the number/size of holes the oil is forced through (requires machining), or change the oil weight.

Also from all I've read, thoroughly draining and refilling the oil is enough work that it wouldn't make a lot of sense to go through the trouble of changing fork oil weight without also swapping in Progressive springs, which only run about $70.

But for me so far this is all book (forum) knowledge. I'm sure if you have more specific questions, you'll get far better answers from those with actual experience.

Mittzy said:

There was an earlier post about changing the oil weight. Can anybody recall this?

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I recall that too but got no idea what the thread title was