I just bought a '72 FJ40 and realized that three out the four (drum) brake cylinder's are seized and one of the grease seals is leaking bad.

Since I have to replace the brake cylinder's, I am wondering if I should, instead, take the money that I would have spent on the new cylinder's and use it towards a disc brake conversion.

Questions I have:

  1. What are the Pros/Cons with doing a disc brake conversion?
  2. Should I convert the rear drums to disc, too? (Assuming I can afford it).
  3. Will I need to get new wheels if I convert to disc brakes?
  4. I plan on staying true to "stock" on my FJ40 - Will converting to disc brakes take away that "stock" vibe? or is a disc break conversion a welcome addition regardless if it wasn't a stock option back in the day.
  5. Are disc brake kit conversions the ideal solution? or is there a better way of going about the conversion?
  • In re: #4. I don't think it matters, personally. If you can do a proper conversion disc brakes are far safer (and IMHO easier to maintain. Servicing drums has been nothing but a pain on all my vehicles.)
    – Robbie
    Jun 8, 2012 at 20:08
  • Disc brakes don't grip well when they get wet, which can be a problem when off-roading. Their advantages (self-adjusting, easier to service, less fade when hot) more than make up for this, though.
    – TMN
    Sep 4, 2012 at 17:38

4 Answers 4


Most conversions fall into three types. A direct replacement from a similar vehicle maybe a later year that came with discs. A system transplant from a factory equiped vehicle not necessarily the same brand. A complete custom sytem from an aftermarket source.The pros are the same obvious reasons new vehicles come with disc brakes.They self adjust, they stop better, they don't fade under hard use like a drum does, repairs are easier and more reliable. The cons of a conversion are, will you remember what the donor vehicle was five years from now when you need parts, if you are far from home and break down the parts may not be readily available. You can get Mustang brakes anywhere but try to find a Wilwood caliper locally on a Saturday night. As far a four wheel versus two wheel disc all the advantages carry to the rear as well. I can't speak for Toyota but I know the factory GM drum wheels would not fit over a disc caliper. Most aftermarket kits are performance systems with large rotors that require at least a 16" wheel, you might avoid this if you can use a stock system from a donor vehicle that had 15" wheels. Also most conversions use the bolt pattern of the donor vehicle. If isn't a Toyota donor car your wheels most likely won't fit. Unless it is a concourse quality restoration most people will approve of the discs.


Later model 40 series does have front discs, but as far as I know you will need brackets welded for holding the calipers. You'll loose your parking brake, so you have to think about that too.

I know that TSM have a kit for the front and 2 others for the rear that don't require welding, but I never read feedback for thoses kits. They claims that the 15" wheel will fit over the new setup.

Another option have seen is to switch to a 60 series axles (front disc and rear drums).

Don't forgot to buy the right sized master cylinder and brake booster for your new application.

Here's a thread on IH8MUD that talk about disk brake swap.

And for #4, I do love stock Land Cruiser (I own a stock HJ60), but if you are looking to sell it to a purist or to go to show with that truck, keep everything stock as possible. Otherwise it's yours, so you do what you want!!


You won't lose e-brake as it is located on driveshaft. Nice feature of FJ-40. With front hubs locked you get 4-wheel e-braking.


My '71 FJ40.. The 4 Wheel drums, The mighty Cruiser's weak link, were a disaster, always were, leaky wheel cylinders and so many of them! 5 years ago I went with the JT outfitters disk kit.. front and back. When you do something that is so much more safer..You are not desecrating the mighty Cruiser. I keep mine quite stock (no lift no huge tires no cutting of body) Over 35 years of owning this 40, The best thing I ever did (other than buy it) was install the disc brakes...Period

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