Drum to disc brake conversion?

I wouldnt spend the money and effort on disc brakes in the back, there is reason toyota is still using drums on even the new tacomas. The tundra brakes make a massive improvement, especially when paired with a t100 booster and master. DM for details if interested in what parts are necessary.

 

Why limit that info to a DM??

You should post that in a how-to thread if you haven't already. Tons of people would be interested in that.

 

I think older Tacoma's would benefit from the t100 BMC swap. My 2001 pedal feels great.

 

Just an FYI to those out there wondering why anyone would be crazy enough to remove the LSPV - most vehicles come with a fixed rate proportioning valve, including many full size pickups. You can very easily follow a guide and get a manual PV like the wilwood unit dialed in to work in pretty much all driving situations.

 

It's not about driving conditions, it's about weight.

Set it up to drive perfectly when it's empty, sure. Then throw a load of rocks or dirt bikes in the bed and all of a sudden it has insufficient braking power.

 

I couldn’t disagree more. While in theory you are correct, in practice that’s just not true. Do you think all 1 ton trucks have LSPVs? They don’t, and yet somehow they stop fine with an empty box as well as a fully loaded box. I understand the advantages of the LSPV, but is it necessary? Ask someone who has done the conversion or owns a different brand pickup and hauls heavy stuff.

If it was that critical to have variable PV for hauling weight, every truck including dump trucks and triaxles would have something similar

 

Just an observation..

I went from an '03 4Runner with 4 wheel disc, to a '15 Taco with rear drums, to a '19 4Runner with 4 wheel disc. I have towed and hauled with all 3.

The ONLY difference I ever noticed was that the Tacoma had a much better parking/emergency brake.

It saved my ass on 1 occasion (idiot moment) when I backed my boat down a ramp and set the parking brake, got out of the truck and left it in reverse! I walked out the pier and nearly shat myself when I realized what I did. My brother hopped in and threw it in park. But, it never budged, on a hill, in gear.

So, if having a strong parking brake is a priority, I might just keep the drums. On that note; maybe the availability of a manual transmission on the Tacoma is the reason for the drums. Not everyone leaves them in gear when they park, so the parking brake needs to be as strong as possible.

 

I'd like to see you argue this point in front of some Toyota engineers, and how you're trying to compare a dump truck, or even a 1 ton truck, to a Tacoma. Apples to oranges my friend.

And by "stop just fine" have you measured stopping distances loaded/unloaded and with/without the LSPV? Or are you just going by the seat of your pants, and "I haven't gotten in a wreck yet, so it must be fine."

 

I’m not arguing the benefits of the LSPV, and I’ve made sure they’re working correctly on all 3 of my tacos and my dad’s tundra. I’m just saying that it’s not an essential piece of equipment, as evidenced by the hundreds of millions of vehicles ever made without them. I think we can all agree that when you’re hauling or towing any amount of weight, driving style is the most important safety aspect. Obviously the brake system is engineered to a very high degree on these trucks and it works really well, all things considered. Your comment that putting a couple dirt bikes in the bed of a truck causing insufficient braking power is something you must have come up with from the seat of your pants. What does insufficient mean to you? LSPV or not, added weight increases braking distance. It’s not usually a function of brake system performance, it’s a function of available traction from your tires. If you can lock up the rear tires with an LSPV or a fixed PV, the brake system is giving plenty of braking power. If you can’t use that brake force because your tires are breaking traction and sliding, that’s where the insufficient part comes in. Set your PV to lock up the front brakes just before the rears do, and your brake system is sufficient. Disc vs drum, LSPV vs fixed PV, it doesn’t matter.

 

"Essential" is a moving target and depends on personal tastes and choices. I wasn't using the term "insufficient" to imply that the truck will explode.

This is not something that I've come up with from the seat of my pants. It's physics. Weight/inertia vs. friction coefficients.

I think we both would agree that stopping distance IS affected. At least on paper. Stopping distance increases because you have added weight, but not added braking power. Theoretically, you could increase braking power to the point that an increase in weight doesn't lengthen the stopping distance, or even shortens the stopping distance.

In fact, look at 18 wheelers. They have a shorter stopping distance when fully weighed down because their brakes are designed to have weight on them. The compromise there is that their wheels lock up easily when empty, and for the average Joe driving a pickup truck, that's not safe. Class A drivers are much more highly trained (presumably, lol).

So if you think about it more like setting up the brakes for max weight like the 18 wheelers, the LSVP is effectively decreasing the braking power to the point that the wheels are less likely to break traction when the pickup truck is empty, which decreases the chances of a skid. That said, I doubt Tacoma brakes are powerful enough to have a shorter stopping distance when fully loaded like the 18 wheelers. But the whole point is to reduce the risk of a skid when UNloaded.

With a manual valve, you are basically either going to make your brakes overpowered (skids easily) when unloaded, or under powered (stops longer than it otherwise would) when loaded. Unless you are constantly adjusting it, that is.

Now can you get that valve to that "perfect" position where it's not enough to notice? Maybe. But now we're back to the "good enough" thing.

 

All good points. Point being you CAN make any valve work, but whether you SHOULD or not depends on the situation and use case. If the stock system is in good working order and fits the bill, then there’s really no reason to mess with the brakes. If you swap to rear discs, it is a good idea to make sure whatever setup you go with gets the correct pressure to operate them.

 

Are you guys easily able to make your front lock up? I have 33s and can barely get it to lock up when I stomp on it with my tundra brakes. Could this be a bleeding issue, or possibly a need for a new brake booster after 320k on the original?

 

I would say you are having an issue with something in the lines or booster if you can’t lock up the fronts with the 13wl setup. Without any further info it’s hard to diagnose