Rear Brakes ('84 720)

[Gofer]

Hi all, looking for advice, guidance or maybe a wake up call. 

 

The rear brakes on this rig were seized when we first moved it (free now) and with it being a drum/shoe I was wondering if there is any way to easily (relative term I know) and economically switch to a disc brake set up?  I have seen the prices on Rock Auto for the drums and shoes, the local shop price floored me, so I thought why not switch. 

 

Please let me know what works in terms of bolt on parts that are available with minimal modifications.  If it is going to be a lot of work and costly, then it will wait until we end up doing a full rebuild on the truck in a few years.

 

Glad to have all your experience to draw from, thanks for the help.

[Gofer]

Guess it shows with me being a Forum rookie,  the truck is a 1984 720 King Cab 2wd.  As this will be my daughters vehicle we are looking to make it as safe as possible for her and better brakes could be a valuable upgrade for the cost.

[Stoffregen Motorsports]

A couple guys here have done rear disc conversions using Isuzu Trooper parts.

 

There are other ways too.

 

I think the two most important parts of a rear disc conversion is the parking brake and the type of caliper. No parking brake=no deal. Floating calipers aren't designed to "float", they are designed to re-center themselves with the pad wear.

[RLJ]

Agree, and not a parking brake by activating the hydraulic fluid to the calipers. 

[Gofer]

Thanks guys, that is a great point that I had not thought of.  Makes me glad to be able to  ask lots of questions that will keep me on the right track.

[datzenmike]

The rear drums don't necessarily need replacing, they can be 'turned' on a special lathe to true them up. There is a limit to how much can safely and legally removed. If they have never been turned you should be alright. Lord knows where the replacement drums are cast, I'm thinking China so you would be wise to have them trued up anyway. Keep the originals if possible.

 

A shoe set can't be more that $50. I found NAPA shoes for about $30 and some Wagner ones for almost $70- Canadian so US would be lower.

NAPA rear drum was $94 Canadian. That is IF you actually need them.

 

So drums and shoes from $225 to $255 Canadian. US would be less. Wheel cylinders from $20-$40. Say $300 Canadian or roughly $240 US. How are you going to convert to rear disc for that amount? You'll need new calipers, new pads and new rotors plus some kind of mounting bracket. Then there was the aforementioned E brake cable hook up if you want it safe for your daughter and the not yet mentioned replacement of the residual valve in the master cylinder. Then your time making it work or paying someone.

 

 

[Charlie69]

Rock Auto Centric brake parts have worked out well for me in the past.  I get the dailey driver level no the economy parts.

 

https://www.rockauto.com/en/catalog/nissan,1984,720+pickup,2.4l+l4,1210329,brake+&+wheel+hub,brake+shoe,1688

 

[Gofer]

Thanks for all the feed back, you are confirming that while it would be nice the most likely answer is that it will be a lot of work and costs with no rel guarantee that it will provide a significant return.  I will remove the drums and see about getting them trued up, and get some new shoes. I am also going to replace the front rotors and pads so she has fresh brakes all around, and to ensure it passes the out of province inspection.

 

[bottomwatcher]

I replaced drums a few years ago. They were not very expensive but if I were to do it again I would have the new drums checked on the lathe. They were duralast from mexico. I felt like they were not perfect right out of the box.

[datzenmike]

This is true. Out of round presents with a pulsing sensation on the brake pedal.

 

 

Rear discs don't stop better than drum as the rears barely do up to 40% of the braking, but they are immune to fade from heat build up. ( a very rare condition unless careening down a mountain with a loaded trailer)  They have fewer parts, less to go wrong and best of all virtually no maintenance except inspection. Pad replacement is super easy compared to drum. Generally disc are easier to modulate close to lock up than drums. Disc are less affected by submersion in water.

[Charlie69]

Much easier to swap pads than to remove Datsun/Nissan rear drums

[datzenmike]

Absolutely but you have to have them first.

[bottomwatcher]

I wish all the other brands of vehicles I have had such easy pads to swap. Can't beat not having to remove the caliper first to swap the pad. I am not sure of the later ones but the 82 is just 2 clips, pull the 2 pins, pull the pads and reverse the cycle.

[datzenmike]

The '78-'82 620 and 720 front discs were pretty much the same solid dinner plate and small caliper and pads. The later '83 and up and D21 Hardbody calipers and vented rotor are a nice upgrade and no rusted in place pins to pull out. The larger pads have clips to hold in place. I believe you just swap the hub with the rotor and caliper. Maybe the spindle also, someone will say, but was for the heavier '83 so will be really nice on the '82.

 

There is also the even larger caliper on the VG powered Hardbody that will work.

[Charlie69]

When I upgraded my 1980 720 chassis under my 66 520 to vented rotors I also installed Belltech lowering spindles at the same time.  But to run the vented rotors you have to change the spindles also.

[datzenmike]

So everything then, ok.

[bottomwatcher]

82 and older 4x4 spindles are different I don't think it will work. The best upgrade I did to the 82 was swap the original single diaphragm booster for a dual diaphragm booster from a frontier. Can lock the brakes with my big toe. 82 and earlier had single diaphragm boosters.

[datzenmike]

...and why the spindle is also changed. Unless this swap only applies to 2wd.

[Charlie69]

I am talking of 2wd only.  My back and neck can not with stand 4 wheeling any more so I leave them to the healthier and younger people.

[Gofer]

Hi Guys,

 

I have a new problem, when I but the bolts into the threaded holes (after triple checking the size and cleaning them out) I started to tighten the bolts a little a t a time and then I start hearing "ting" and the threads broke out of the holes.  What is the best way to remove the old rusty drums now?  

 

Thanks for you help, I need it.

[Charlie69]

Back off the adjusters first.  I spray a little WD-40 on each stud where it enters the drum and the center hole in the drum for the axle.  I take a 2 Lb one hand hammer and tap lightly all around the outer edge of the drum face.  I then take two short pry bars and work around the inside edge of the drum prying between the drum and the backing plate.  If I do not get movement then I keep repeating the process until I get the drum moving.

[bottomwatcher]

I know in the past I stuck self tapping bolts in the holes. Not the sharp pointy kind but the blunt type with the notches in the end. Slightly bigger bolts have a lot more threaded area to spread the load and the original threads were probably barely there from rust, a little heat outside where the drum centers on the hub. This interface is where it gets stuck. Like Charlie said some hammer persuasion. This is where vibration us your friend.