Need info - Installing new cam seals in 170 HP Mercruiser 470

[Dave WJ]

Hello all & thanks. Been using this forum for years to find info. It's wonderful, but I can't find the answer for this.

When installing new cam seals in the front water pump, what do you press them in with? Reading the instructions and looking at my new seals, I assumed I would be pressing them in from the back (oil side) and would have the flat metal part of the seal to push/tap on, so the open spring sides would be toward the coolant. But when I got everything apart I realized the oil side of the cover has a lip on it for the first seal to bottom out on, so obviously they have to go in from the front. What I don't know is what to press them in with. It seems to me anything, even if it was a perfect fit, would mess up the new seals, as there is nothing but rubber on the open spring coolant side. Am I, as usual, missing something simple? Thanks.

 

[philbullet]

Did u remove the complete cover plate? U will have to remove crank pully/balancer to do so.I did mine a few time and used a socket thats the right size to tap in.
They make a triple seal to replace,at lease the place that i bought mine from did.They go with flat side facing toward inside,one to keep oil out and the other yo keep anti freeze coolant water out.If one or other come's out of weep hole it's bad seals,most likely the water side.Hope this help's.

 

[Dave WJ]

Thanks philbullet. I overheated, and looking for the problem found coolant coming out the weep hole. First thing I did was run a compression test. Completely cold, I got 120 all 4 cylinders +/- 4%. I have pulled the rotor and removed the complete front cover. I know how they go in, but they will only go in from the front, which places the flat metal side going in first, so I would have tap it in by tapping on rubber - no flat metal surface, or any metal, on the front open side to tap on. Seems like this will ruin the rubber, even if the socket was a perfect fit.

 

[stonyloam]

They make a triple seal to replace,at lease the place that i bought mine from did.They go with flat side facing toward inside,one to keep oil out and the other yo keep anti freeze coolant water out.If one or other come's out of weep hole it's bad seals,most likely the water side.Hope this help's.

BOTH seals face (spring side) the coolant. They do not keep oil out, one keeps coolant in, and the other keeps coolant out of the crankcase. Works like this: the two seals are installed with a space between them, with the weep hole opening into that space. The forward seal seals in the coolant that is under pressure. If that seal fails, coolant under pressure leaks into the space, and the weep hole drains the coolant. Since the coolant is no longer under pressure, it just dribbles out of the weep hole and the second seal keeps it out of the crankcase. While you have it apart, make sure the weep hole is clear.

 

[Dave WJ]

Stonyloam, I was hoping some of you 470 guys would help me out with this. I understand which way they go in and work, i.e. first one in until it bottoms out - second one in until it's flush with the front of the cover, both spring sides facing coolant, space between them where weep hole is, and I have made sure the weep hole is clear. What I don't know is how to tap them in from the front without damaging the rubber. I'm sitting here looking at the seals, and they have a flat metal (back) side, and the open spring side which has no metal surface to tap on. Even the metal rim of the spring side has rubber on it. Won't putting them in by tapping on the rubber mess the seal up? Do all the covers have a lip on the on the back (oil) side, so the seals have to go in from the front? If not, would it help if I posted pictures of the seals and cover, so you can see exactly what I'm talking about? Thanks much.

 

[stonyloam]

I did mine so long ago it is hard to remember. I think I used a wood block to drive the first seal flush, then used A socket to drive it home. Should not damage the seat, they are pretty tough. As far as I know they are all the same.

 

[Dave WJ]

No Title

OK, I know you 470 guys have seen these hundreds of times, but just to make sure I'm not explaining this the wrong way, here are photos, 1, 2, and 3, of what I'm asking. Photo 1 showing 1/16" on backside of front cover, making it necessary to install seals from the front. Photo 2 showing back (oil) side of seal. Plenty of metal to put a socket on and tap in, IF they could go in from the back, which they can't. Photo 3 showing front open spring side that faces coolant with arrow pointing to the very thin outside rim with rubber covering it. What I don't understand is how I can tap the seal in on the open spring side without damaging the rubber. Am I missing something here?

 

[SDSeville]

They are pretty sturdy, especially the outside ring, which is where you put the socket or whatever you use do tap it in. You don't bang on the inner ring (the one with rubber and spring) during installation.

 

[Dave WJ]

Thanks everyone. Got them installed. With Locktite on them. That outside rim with the rubber over it is tougher than it looks. Started the first one in with a flat piece of wood using my drill press to press it in flush, then found a piece of PVC pipe that was a PERFECT fit to press it on down till it bottomed out. Then used the wood again to press the second one in until it was flush. Thanks again!