How much do big tires effect brakes?

[jperry1290]

When I bought my EB it had 235's on it along with drum brakes. I just added 33's to complement my 3.5inch lift and ran all new brake lines. Before the lift the brakes worked very well at stopping, but after adding the new tires it takes a little longer to stop. I have bled the lines to make sure that all the air is out. Anyone else experience the same thing?

[bronko69er]

Re: How much do big tires effect brakes?

What do you mean by taking longer to stop, is the pedal hitting the floor?

[CityHick]

Re: How much do big tires effect brakes?

Larger tires translate into a larger rolling mass - think of them as a heavier flywheel. Its harder to stop a heavier rolling mass, so yes, you can expect degraded braking performance. If you're certain there's no air in your lines then its probably normal. Might not hurt to bleed the system again. If you replaced your master cylinder or let it go dry when you replaced the lines, did you bench bleed it before hooking up the lines? It can take a while to get all the air out of the master cylinder had air in it.

Are you still running stock manual drum brakes? You're getting to the point where upgrading your braking system would probably be a wise choice. I run 37" tires with disk up front, stock drum out back and a Tom's vacuum booster (a bendix booster). I can lock up all 4 37" tires without too much effort, but it certainly doesn't stop like a sports car.

[earlybronco72]

Re: How much do big tires effect brakes?

I ran stock manual drums all the way around with 37's for years. I could lock up all four, but it did take a lot of leg. Make sure your brake are adjusted properly also.

[Fungus232]

Re: How much do big tires effect brakes?

Larger tires translate into a larger rolling mass - think of them as a heavier flywheel. Its harder to stop a heavier rolling mass, so yes, you can expect degraded braking performance. If you're certain there's no air in your lines then its probably normal. Might not hurt to bleed the system again. If you replaced your master cylinder or let it go dry when you replaced the lines, did you bench bleed it before hooking up the lines? It can take a while to get all the air out of the master cylinder had air in it.

Are you still running stock manual drum brakes? You're getting to the point where upgrading your braking system would probably be a wise choice. I run 37" tires with disk up front, stock drum out back and a Tom's vacuum booster (a bendix booster). I can lock up all 4 37" tires without too much effort, but it certainly doesn't stop like a sports car.

What Tony said! I run a hydrobooster w/ 33" tires disc/ drum and it DOES brake like a sports car. The Bronco brakes better than my '04 F-250 and my wife's '08 Saturn SUV.

[jperry1290]

Re: How much do big tires effect brakes?

I will get the disc's up front some day and hydroboost, but probably not for a while. The pedal doesn't touch the floor it just goes down about 3/4 of the way. I had bled the m/c before hooking up the lines.

[blwngsket]

Re: How much do big tires effect brakes?

33's shouldn't effect braking much if at all. I was able to lock up 14-35-15 Monster muddders, no problem with stock brakes. I now have 4 wheel disc brakes, Hydro boost and 39.5's.

Now, thank god for 4 point harness's or I'd face plant into my windshield..............

Power bleed your brake system. Sounds like air to me.

[71BRONCO71]

Re: How much do big tires effect brakes?

bleed the rear first ... Passenger side then driver side. Then front driver and front pass.

Mine stopped fine with 33's and manual drum brakes.
Now if i could only get my arse to the junkyard to grab a hydro boost unit.

[blwngsket]

Re: How much do big tires effect brakes?

If you could only FIND your arse young grass hopper

[71BRONCO71]

Re: How much do big tires effect brakes?

If you could only FIND your arse young grass hopper

YOU ARE THE GRASSHOPPA! I am Mr. Miyagi.
Now for your first lesson ...

[welndmn]

Re: How much do big tires effect brakes?

When you're just sitting there, can you pump up the brake pedal and make it go firmer?

Have you checked all your wheel cylinders for leaks?
While adding a larger tire/more weight will increase your stopping distance, if your braking system in still in proper working order, this "feeling of taking longer" might just be in your head.

[Spaceburger]

Re: How much do big tires effect brakes?

from the movie "Dutch" 1991 (Ed O'Neill): "You can't beat a Ford for good brakes!"
I burned allot of time getting mine to stop right. Make sure your brake shoes are free of any grease, drums are clean and machined flat, and your rear axle seals or brake cylinders don't leak fluid onto the drums.
Both my broncos have power brakes, stock Ford disc brakes w/ new calipers and rotors, in front, new rear cylinders, clean drums, new brake lines (steel and soft), and most important: new proportionuing valve.

[blwngsket]

Re: How much do big tires effect brakes?

YOU ARE THE GRASSHOPPA! I am Mr. Miyagi.
Now for your first lesson ...

The force is strong in this one.... Or is that Farce
You Grasshopper and beer is MINE.........................

[Broncrick]

Re: How much do big tires effect brakes?

Replaced my whole system, booster/master etc and flushed the fluid by gravity several times (dang 40 yr old parts). Found a vacuum problem that solved the rest. Good luck!