78 FJ40 FD Brake Rotor Replacement - Contingencies (1 Viewer)

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Getting set to replace original front disc rotors. Apologies if this has been asked but no thread titles seemed promising.

I'm concerned that I'm going to crack it open and be caught needing to replace parts I don't currently have. I'm looking for guidance on what I can expect will certainly need replacement so I can set myself up for a proper rebuild in advance.

Hubs are original Warns. I should expect to replace gaskets, etc. with a rebuild kit.

While I'm in there, and since my knuckles have leaked grease for years, new felts etc.? I'd really prefer not to go that far, but if educated opinion suggest I should, I'm open to going knuckles deep. Trunion bearings? Etc.

I do have the 54mm socket. Check that off the needs list…

If there's video(s), please point me in the right direction.

with thanks. Michael
 

RWBeringer4x4

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I'd strongly recommend, if you're getting a runny combination of grease and gear oil running out of your knuckles, that you take the time to do a full axle re-seal. It might not hurt to also grab your tires (while they are suspended/truck is on jackstands) and try to shake them. Any "play" in the tire generally translates to worn trunnion bearings or wheel bearings. The truck may not NEED new bearings, but they are (relatively) inexpensive so it might be worthwhile to throw some new ones in while you're in there.

Also - pay attention to the condition of your brake lines (soft and hard). I am in the process of overhauling my axles (removed them entirely from the truck), and one of my hard lines actually snapped when I was trying to loosen it from its connection. They tend to rust from the inside so it can be tough to tell whether or not failure is imminent. My plan was to replace all the hard lines anyway but this was all the more justification to do so, for me.
 
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thanks for the good thoughts RWB.
I have braided flex lines done a while back, but the hard lines are older. I had actually locked up the brakes maybe 15 years ago to avoid an accident, and when I went to get rolling again, pushed on the pedal which went to the floor. Hopped out and found I blew right through. A few years before when I was flat bed towed for a blown radiator by-pass hose, the tow operator threw the hooks right over the axle instead of using the tow eyes, and mashed both front lines for me. idiot.
 
Joined
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keep trying to phone Marlin and they're "closed for the night". it's about just about 2pm EST

oh, closed Fridays. wtf. business must be good.
 
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impossible to reach these guys.
outgoing message says my "call is important, try back in a while."

how many whiles does it take? really.
 

Racer65

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At what rotor thickness do you guys determine it's necessary to replace it?

I measured mine to be exactly 20 mm, which is what the Haynes manual calls "Standard" thickness. However, 19 mm is the minimum thickness.

Just put in new pads. Was going to do the rotors if it was simple job like on most cars, then I looked at the video and learned how much work it involves.
 
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I've had trouble getting in touch with anyone at marlin through email or phone in the past.
If your looking to order the marlin seal I would use cruiser outfitters can't beat the service from them. Might be able to answer a quick question on your brakes as well. That marlin seal is the bees-knees for our 40s from what I've read, mine are sitting in the box waiting to go on.

Good luck to you, this project is on my to do list once I get mine back.
 
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Yep. If you've got leaking knuckles, it probably means that there's diff oil in your knuckle grease because the inner seal leaks. Even new felts won't hold that back.
New inner axle seal is in order. Kurt at Cruiser Outfitters can sell you everything including the Marlin Seal.
Great guy to deal with.
 

Howard705

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If you want to cut corners/save time/money/etc- just throw pads on it if the rotors aren't junk-will take longer to break in but will work fine. Or if you're doing rotors anyway and don't want to mess with pulling the knuckles-which is a pain-just pull the spindle and put the axle seal in (and repack the birfield)-it probably will stop leaking at the knuckle.
 

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