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Rear discs FTW!!!!!!!


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Been 2 weeks now trying to get the rear drum adjusters freed up on the '85 BRAT I just bought. Found no happiness there, even after giving them a shot of penitrant twice daily during that time. No joy, period..... Had way iffy brakes with low pedal, couldn't improve them any by bleeding, but I do have fresh fluid thru system now.

 

Had parts to do the conversion, but rotors were worn and calipers didn't look to appealing. Got better rotors and calipers from john in KY. Yea!!!!!

 

Pulled drum stuff off, put disc stuff on, re-bled system. Gots a good brake pedal now. Did a road test after insuring that things were good to go. Doing 55 MPH and nailing brake pedal pulls her down to a crawl very quickly. I be liking that.

 

BRAT stops with no pull to either side and minimal squeal from tires. Repeated the "panic stop" 3 times with same results. I be a happy camper now. Wife be happy too, as she can now drive "HER" BRAT.

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If you lockup all 4 tires on wet pavement it may lock the rears first and cause a loss of control without the proportion valve in place. That was my experience - adding the valve corrected it and mine stops perfectly straight and level now.

 

GD

 

Do brats not have a proportioning valve? On ea82s, whether drum or disc, the valve function is the same. Only the last foot of line at each wheel needs to be changed.

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Where would I find this valve on an EA-82 vehicle. Might as well do the job right.

 

 

If you lockup all 4 tires on wet pavement it may lock the rears first and cause a loss of control without the proportion valve in place. That was my experience - adding the valve corrected it and mine stops perfectly straight and level now.

 

GD

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My RX Stopped Very fast with its 4 wheel discs, but i didnt like how going through a carwash or deep snow left me nearly without brakes for like a mile down the road.

 

That can happen on any car. Your brake pads get wet and it takes a few yards for the moisture to evaporate. When you get that wet, just ride your brakes for a little bit.

 

The proportioning valve is in front of the rear axle on the drivers side.

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The proportioning valve is in front of the rear axle on the drivers side.

 

He speaketh the truth. It's on the "wall" that exists where the floor of the inside of the car rises to meet the bench that the rear seat foam sits on top of. If you follow the brake hard lines back to where they enter the cabin you can't miss it - it's right before that. Take all the hard lines you can get as well when you pull it - they can be easily bent to your needs in order to accomidate the Brat. I mounted the proportion valve on two of the same bolts that hold the fuel pump tray. Worked well for me.

 

I decided I needed the valve when I took the Brat for a skid test immediately following the swap - it was wet and under a full lock-up I did a 180 and ended up half in the oncomming lane facing the opposite direction that I started. After adding the valve (and later the same day on the same bit of road) it skids 100% straight. The problem is that the Brat's rear end is so light that the added clamping force of the discs makes full pressure lock the rear wheels before the fronts and results in a situation where the rear end trys to pass the front because the coefficient of kinetic friction is less that that of static friction - thus the rear wheels speed up as soon as they start to skid (this is also the principle behind ABS brakes).

 

GD

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Thanks for the info Turbone & GD.

 

I know only to well how pick-ups like to have the rear bumper out front when you brake hard. BTDT!!

 

Now to locate one.. Wish I had the knowledge of this valve awhile back. I scrapped an '86 Sedan, didn't know of valve. Darn it!

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I decided I needed the valve when I took the Brat for a skid test immediately following the swap - it was wet and under a full lock-up I did a 180 and ended up half in the oncomming lane facing the opposite direction that I started.

 

GD

 

 

 

Humbling!

 

I wonder how easily this valve would retrofit onto various other vehicles... Hmmm...

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Humbling!

 

I wonder how easily this valve would retrofit onto various other vehicles... Hmmm...

 

Eh..... you can get aftermarket adjustable ones from summitracing or other places for pretty cheap. It wouldn't be worth the effort since both circuits run through the stock valve and the aftermarket ones are smaller and control only a single circuit so you don't have to run lines all over the place to get the job done. I was half considering using them for my Brat as it would simplify the plumbing and make it adjustable for rally-x. Being able to kick the a$$ end around on command isn't neccesarily undesireable for such events ;)

 

GD

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