Sierra Brake Limitations

[Highway-Star]

Ok, there has been a million and one topics on upgrading brakes, disk conversions, master cylinders, boosters etc. However I cannot find any mentioning of when the standard brakes on a Sierra are inadequate.

I figure there are two main modification items that have a noticible effect on braking, tyre size, and weight increases. What I am after is a rough guide for when the brakes should be upgraded to suit a certain amount of extra weight and/or a certain size tyre. Theres also the handbrake to consider, because it only just holds now as it is on a hill.

I know that the standard WT brakes stop the car like a brick wall, I assume this is becasue the brakes were originally engineered for 28" tyres, not the 26's that the WT has, agree anyone? So I assume anything up 28" would be safe, with any sane weight increases. Just planning ahead, and need to factor in any costs for essential upgrades for the running of larger wheels.

Also I'm not keen on hearing, "just try it and see how it goes", or "She'll be right mate". Brakes a serious, and should be the last thing to be ignored.

[Guy]

Ok, there has been a million and one topics on upgrading brakes, disk conversions, master cylinders, boosters etc. However I cannot find any mentioning of when the standard brakes on a Sierra are inadequate.

I figure there are two main modification items that have a noticible effect on braking, tyre size, and weight increases. What I am after is a rough guide for when the brakes should be upgraded to suit a certain amount of extra weight and/or a certain size tyre. Theres also the handbrake to consider, because it only just holds now as it is on a hill.

I know that the standard WT brakes stop the car like a brick wall, I assume this is becasue the brakes were originally engineered for 28" tyres, not the 26's that the WT has, agree anyone? So I assume anything up 28" would be safe, with any sane weight increases. Just planning ahead, and need to factor in any costs for essential upgrades for the running of larger wheels.

Also I'm not keen on hearing, "just try it and see how it goes", or "She'll be right mate". Brakes a serious, and should be the last thing to be ignored.

I ran around with 33 bias swampers and 35 bias claws (The claws wrer about 40 or so Kg per wheel and tyre) and found the stock front brakes to be adaquate, when on swampers I would travel to essendon to oakleigh to work each day (bout 50 ks of mixed freeway and surface road traffic)
I never found the brakes wanting. (well the rears never did anything anyway)

[nicbeer]

same here. fronts never had a main issue with but a vit conversion for the front came with my front cut so i used them.

I did the rear disc conversion now and still modding it a little bit with bias valve but can lock all 4 up easy as now.

Nic

[Bazooka]

When I did the 4AGE conversion it was happily passed using only a Ford remote booster for the stock 1L front brakes. I ran like this for years until getting my hands on some Vitata front brakes. Realising how much better they were I went and converted the rears to disc. Now they are so much better then the stock setup I don't know why I didn't do it earlier. I'm only running 235/75 tyres but thats beside the point. I am much happier with the upgraded brakes no matter what size tyre I could be running and feel much safer in any type of emergency.

[Liam]

Before I went silly with mine, it ran 31's on stock diffs, stock brakes never had a drama or found them lacking for stopping power unless it had a trailor behind. Changing rear shoes because of mud got pretty boring though.
The only time the brakes really sucked was towing a recovered commodore on a car trailer (offroad) it really really didn't want to stop (who'd a thunk?)

[Highway-Star]

Thanks everyone so far.

Trailer is relevent for my situation, something I'm glad to hear commented on; though towing a commodore is definitly not on the agenda . I only really have a towbar for an unbraked 6x4 box trailer for camping gear.

Love_mud, even though you say you ran 33's and 35's with standards, thats something I don't think I could bring myself to do (I don't plan on going that big anyway), interesting non-the-less.

[MUD-PIGSIERRA]

I have converted rear disks on mine and find them to work pretty well with 31"s. My previous WT Sierra ran on 33"s for a while and I could feel that the brakes where struggling a little to slow it when I really needed to stop quick, I was often slowing down early at lights and doing under the speed limit just in case someone was to pull out.

If anything I try to not let my brake pads get to low so the pistons dont have to move a great amount or are allready almost fully extended, that and clean brake fluid and it brakes quite well at the moment. Maybe people could recommend some good brake pads they are using on the standard setup...?

[Bazooka]

Yes I must also add it has made stopping with a load much better. Dumped a few hundred Kg's at the tip on the weekend and it pulled up much better than stock brakes ever could. Didn't even have any problems on the hills

[nicbeer]

I have converted rear disks on mine and find them to work pretty well with 31"s.

did u mod the booster or run a bias valve?

[Gwagensteve]

I think sierras have excellent brakes, even with bigger tyres. Drive an 85 hilux with 32" tyres and get back to me....

I will go disc rear, but mostly because of serviceability. I actually have no intention of going to boosted brakes - I like the feel of them unboosted.

Highway-Star - I think that whatever you plan for your car, the stock brakes will be well up to handling.

Steve.

[ofr57]

mud4b did a disc transfer case handbrake on his coily .... later on I'll most likly get him to do one for my ute

I'm happy with the 31s an stock brakes ... hand brake on other hand is almost pointless atm

[Gwagensteve]

I adjusted up my stock 1.0 handbrake and it was amazingly good.... for about as long as the stock non self-adjusting 1.0 rear brakes were any good.... which was one trip

Steve.

[Jaffa]

Sorry to hijack, but what do people think about using a line lock to aid the crappy sierra handbreak like down the bottom of this page http://www.lowrangeoffroad.com/sambrakes.htm , do you (steve) think the mechanical one would be alright to use, say when taking off when on a hill (not using instead of handbreak for normal everyday use, but off road only)

[Gwagensteve]

I will... *ahem* in my never ever driven onroad ever ever ever car be hooking the stock handbrake lever to the brake pedal. Did it in the "never driven on the road" Critta and it was the shizzle.

I'd like to play with line lockers as well (for digs/burns), but the handbrake to pedal thing is easier and less visible.

I don't have the facility for a handbrake as I have a disconnect and will be going 1.3 front brakes on the rear.

Steve.

[Jaffa]

.......be hooking the stock handbrake lever to the brake pedal.

Once again, sorry for the Hijack. How is this done (on a purely off road vehicle ) steve? Custom cable though firewall I assume. Would the cable limit or impede the brake pedal movment?

[Gwagensteve]

We Didn't in critta - just welded a short length of tube to the lever to take the sleeve that goes through the backing plate on the drum and a lug to the pedal box mount - all sweet.Never gave any trouble - just went slack when the brake was applied.

In critta, the handbrake was mounted to the centre windscreen bar on the cage so a stock NT cable was fine, but I want to keep the handbrake in the stock spot so I will need a longer cable... maybe WT?
Steve.

[Highway-Star]

Hey thanks people. From what I've gathered, the standard brakes are good, but as I suspected the rear drums need constant maintenance, and thats the reason people go rear disc. I agree with Mud-pigsierra, I'd like to hear any opinions on particular brake pads?

Handbrake is a permanant issue with the standard setup. I remember having to put it in LR, 1st with the handbrake on once to stop it rolling down a hill; and thats only with my little 27's. Then I did some crazy method to 'adjust' the auto adjust which helped. I am rather concerned about the handbrake though, as I regularly park on a steepish driveway at a mates place for going to uni. Do peoples rear discs make a serious improvement to the handbrake?

Drive an 85 hilux with 32" tyres and get back to me....
.

I'll (me on behalf of my father) be needing to know about this soon enough. Thats for the Yota section though. Thanks for the heads up.

[nicbeer]

Do peoples rear discs make a serious improvement to the handbrake?

depends on how u do it.

I have a NT transfer brake so rear discs didnt effect handbrake at all. still crap as ever.

[MUD-PIGSIERRA]

did u mod the booster or run a bias valve?

No booster or bias valve, find them to be pretty even though I have a manual adjusting proportioning valve in the shed just haven't felt the need to fit it. It does skid the rear to the right every time if I try lock it up hard in the dirt.

I heard some people put a grove in the rear pads to give more braking bias to the front or run pads considered to be of less quality and braking grab as well...?

And to add I got the Handbrake drum off the transfer, enough to hold it on small hills and pass rego and thats about it....