Brake proportioning valve.

   

I know this is a long shot but has anyone who has upgraded their front brakes either taken the valve out or replaced it with an adjustable one? 

My car is biased fairly heavily on the front, which is safe, but it dives under hard braking as most cars do. Getting the bias between front and rear makes the car sit down under braking rather than diving and the difference is huge.. Upgrading the front makes the bias between front and back worse.

I plan to upgrade the front brakes soon and so I can try it but was wondering if anyone had an adjustable proportioning valve.
Thanks.

Is it safe to assume that on the tf models where the four pot brakes were used, the brake balance was set in an appropriate manner. It would be a useful exercise if you were to look at the EPC & compare part numbers for the standard valve & that fitted to the higher performance car.
I’m slowly working my way towards the big bolt on of my uprated system, along with four pots, I’ve made adapters to run larger rear discs.
With this instituted the out of balance with the OEM part, if any, should equalise.
Failing that I’ve already eyed up an adjustable proportioning valve, for inclusion if required.
M

You raise a good point!
I would almost bet money that the valves are the same but will try looking up the part numbers to confirm. Manufacturers do bias for safety on the front and I bet they didn't bother about that valve. Guessing.

I think if you run larger rear discs too you will be at manu's specifications or close. I've read on here people upgrading the front and not so much the back.

If and when you feel the need to fit an adjustable valve and set it right the difference in applying the brakes and feeling the car "sit down" is really satisfying.

My 50 year old Celica was upgraded with front brakes from a heavier car, a Corona, which I had shipped from Australia, loads over there. They made the car very front biased and it felt like the back brakes weren't working. I removed the valve and the difference in stopping power was immense even leaving the rear brakes as std. Removing the valve just worked in that scenario but normally you need to have some adjustment handy. 
Locking the rear brakes in a forest gets you round the corners...locking them on tarmac gets you in the ditch!

Just done a quick search and results from folks on the TF Register say that with 4 pot callipers the valve was not fitted.  Then again others reference it to having ABS requirements..

My car does not have ABS and I am quite happy about it.

https://www.mgfregister.org/forum/viewtopic.php?t=17154#p129531

BTW. anyone reading and not sure  just want to say that the valve is sited in the rear brake lines only...the brake line that comes off the front of the master cylinder.

I'm doing a brake upgrade but i'm doing both front and rears  305mm front and 280mm rear
BTW there were loads of Toyota Coronas here but not any more they've all rusted away and been scrapped, rarely see them anymore, and nobody really misses them either.

I think by doing upgrades to front and rear you will probably keep the 60-40 bias intact.
55-45 could be good.
Re Corona's they never sold well over here. Just a big numb faceless car but at the time I needed front struts from the XT130 the scrap yards were full of them in Aus but not anymore.
I can't afford 4 16 inch wheels, tyres, callipers, discs and pads so I am upgrading the 15 inchers.
By the time I upgrade the discs and better pads and sorted out the bias I will have good brakes. Hopefully!

The XT130 was an absolute pig, probably the worst car Toyota ever made, everyone hated them, the engine was total rubbish, XT130s were stacked ten deep at the rubbish tip!

Cobber wrote:

The XT130 was an absolute pig, probably the worst car Toyota ever made, everyone hated them, the engine was total rubbish, XT130s were stacked ten deep at the rubbish tip!

They were hated just as much over here!!  but the struts and the bigger brakes were a bolt on to a TA22 or an AE86 so they at least served some purpose!

EDIT: the 130 callipers were two pot instead of the single pot on the TA22. They were Sumomoto and were fitted to some Triumph 2000's in imperial calliper bolt spacing. I used to have a Brake Pad site that showed almost every brake pad known to man with exact sizes of backplate, pad shape and thickness , and pin spacing. By comparing the XT130 pads I found out they were identical Escort RS2000 rear brake pads. Now a 40 year old Corona you can only get std pads...but for a Ford you can get any amount of competition pads. By fitting Mintex competition pads the brakes improved by 50%.

I've since lost that Site but I will find it again.  I think you know where I am going with this.  

 

You say you’re sticking with the 15” wheels, what route are you taking?
I was 90% ready to fit Mini T53 (?) front callipers & the aforementioned mods to the rear. MGB281 & I had a too & fro a while back on this subject, it might be worth looking up.
I was squeezing through this gap in the fence for the very reason you outline. The cost of doing the job in accordance with the accepted norm & then in short order a set of wheels rolled along then a pair of four pots screeched to a holt right in front of me. A kindly chap sold me some discs at a suitably discounted price due to a few rust spots & knackered boxes. All this at a costs just below the bollocking level. Amongst my other pass times is cheapskating & for a chap (bloke) of my age I’m quite competent.
How thing can turn on a sixpence whilst your intentions are in one direction & fate wants you off at a tangent.
I’d hate to see a vector diagram of my life, with intentions in red & outcomes in blue.
Nothing has been bolted up yet as the wheels are 17” & catch when on full lock, once resolved I’ll be off.
M

"....at a cost just below the bollocking level.."....Please advise what that level is! 

Does the Mini route require calliper brackets made though? The thought of two pots is always appealing especially when they are BIG pots like my pic above.

Finances mean I have to stick to 15inch wheels. I borrowed some money to buy the car from my insurance payout from a van accident, just enough to be below the bollocking level, but I can't buy bits until I sell the MX5 and that is likely to be spring now. 

I do like finding out what you can just bolt on without resorting to fabrication as I haven't the means anymore. 

You are obviously a Master at cheapskating with your purchases....please bear me in mind ...my credit is good!  

Good luck with your project. I am quite sure you will want to fiddle with an adjustable Bias valve. That "sitting down" of the car is addictive.

 

There are always geographical element with this stuff; there’s a chap in Cobber country who requires a wind stop of the open gauze persuasion or alternatively the Perspex variant, I can help in both cases but it’s not as easy as say a day out to Skipton or Crewe, er, maybe not Crewe.
All the brake stuff is hung up in the garage, adapter brackets & refurbished callipers all in a fetching yellow, why red when yellow stands out more.
If you are interested the bollocking threshold depends on far too many variables, if it’s big & expensive I forgo cheap peripheral fripperies & playthings, which means no deliveries for me & she thinks I’m being frugal.
She sees frugality I plan skulduggery. This is a game we have played for over fifty years.
The brakes, just a thought.
M

Airportable wrote:

There are always geographical element with this stuff; there’s a chap in Cobber country who requires a wind stop of the open gauze persuasion or alternatively the Perspex variant, I can help in both cases but it’s not as easy as say a day out to Skipton or Crewe, er, maybe not Crewe.
All the brake stuff is hung up in the garage, adapter brackets & refurbished callipers all in a fetching yellow, why red when yellow stands out more.
If you are interested the bollocking threshold depends on far too many variables, if it’s big & expensive I forgo cheap peripheral fripperies & playthings, which means no deliveries for me & she thinks I’m being frugal.
She sees frugality I plan skulduggery. This is a game we have played for over fifty years.
The brakes, just a thought.
M

Lol.  I play that game too. The Toyota garage I worked for was in Silsden, very close to Skipton and that's where I hung out before I moved to Scotland.