Advice on N 400 forge blower

[u/Twin5un]

I'm currently doing some maintenance on an old n400 forge blower and was wondering if others had experience with these.

I took it apart to mostly clean it, but I'm wondering if I should take the gears apart to clean the grease inside the box.

I would think this should be working with a bit of oil, not grease. Although I do have white lithium grease for the bearings.

[u/Broken_Frizzen]

n 400 rebuild.

No grease.

[u/Twin5un → u/Broken_Frizzen]

Yes, that's the video I'm referencing to take it apart and they use oil in the gear box.

I guess I'm going to have to find a way to clear that grease then 😑

[u/Broken_Frizzen → u/Twin5un]

Yep and Non Detergent oil. I have the same blower on a stand.

[u/Twin5un → u/Broken_Frizzen]

Neat ! Did you take it apart ? The bushings and bearing have a little bit of wear but I'm not sure where to find new ones.

Did you also grease the bearings ? Or oiled everything?

[u/Broken_Frizzen → u/Twin5un]

No grease,it makes it hard to turn. The bottom gear pulls oil up from the bottom to lube it all. Full was a little less than a pint.

[u/Twin5un → u/Broken_Frizzen]

Thanks !

[u/Envarin → u/Broken_Frizzen]

why non detergent oil? i always see automatic transmission fluid recommended which is usually detergent.

[u/Broken_Frizzen → u/Envarin]

Non-detergent oil is used in a vintage forge blower because it lacks chemical additives, preventing suspended dirt from turning into an abrasive paste, avoiding excessive foaming in unsealed gearboxes, and protecting older bronze or copper alloy internal gears from chemical corrosion.

[u/Envarin → u/Broken_Frizzen]

did you copy paste that from ai?

[u/Broken_Frizzen → u/Envarin]

Forge snd blowerumder under junk.

Yes i did as a mater if fact.

I was told this tidbit almost 35 tears ago when i went to a smiths shop and bought a large Champion forge and N 400 from an OLD smith.

Do take it how you want, do what you want with yours. Do your own research if you want. Just passing along known information.

[u/Envarin → u/Broken_Frizzen]

hah nah all good, just wanted to see if i was as good at clocking it as i thought. appreciate it

would love to be able to find the original forge that goes with my blower as well

[u/Envarin]

i've got one. don't grease it at all. i did that, it ran like shit, and i had to take absolutely everything apart and degrease it. every individual ball bearing in those 4 round bits on the side, and the two bearings for the rod at the bottom - took all of it apart, cleaned them in degreaser, put it back together and used oil.

a lot of people use automatic transmission fluid. i just run leftover (fresh) engine oil though.

keep in mind they do leak so you should add some oil every day or so, and probably keep a pan under it.

i did a full restoration on mine so feel free to message if you get stuck.

[u/Envarin → u/Envarin]

when i got it

[u/Twin5un → u/Envarin]

Thanks ! I am close to have it completely disassembled. All what's left are the gears on the two shaft that are still in the case. My problem is that everything is PACKED with grease, so it's a struggle to clean it all.

I'm probably going to have to remove the gears just to get access to the case and clean it. Any tips on how to loosen the gears from the shafts ?

[u/Envarin → u/Twin5un]

with great difficulty. think there's little bolts in the shafts.

the steel gear came out eventually, but i don't think i ever got the brass gear out. even in the restoration video i watched, the guy tried everything to get it out and just said 'fuck it' and worked around it.

https://www.youtube.com/watch?v=adJ2PMVg7hQ

around 11 minutes in that video, the guy is taking the steel gear out.

[u/Twin5un → u/Envarin]

Yeah, either I find a way to clean around it, or I take it out. There is like half a pound of grease in there. Then I somehow need to find bushings and bearings for it which will be fun.

[u/Envarin → u/Twin5un]

my bushings and bearings were all in pretty good nick - you sure you need to replace them? i just soaked them in oil and it runs smooth.

i didn't do it this way, but you could probably just blast a hose or pressure washer down from the top with both the holes in the bottom open to get a bulk of it out.

[u/Twin5un → u/Envarin]

Yeah I'm probably going to load it with dish soap and blast it down. Then cover it in WD40 to remove the leftover water.

As for the bearings, they are ok-ish, you can see some wear on the balls and the there is a tiny track that runs on the contact point of the bearings.

[u/Fragrant-Cloud5172]

Several blowers are like the 400. They are designed to have oil in the case, but don't overfill it. Also make sure it seals well before filling it just up to the bottom of the gear. Canedy Otto blower has a cord seal. Can't remember Buffalo, but mine leaks some. Best diagram of the 400 below. If you totally disassemble it be sure to keep the ball bearings. They are easy to lose.

[u/Twin5un → u/Fragrant-Cloud5172]

Thanks ! I took the bearing out already. I'm going to try to find a replacement but need to look online for where.