Intermitant Spongy Pedal

[carnut]

This system even at its operating best, has a somewhat spongy brake feel. I recommend using organic pads for a better feel. Semi metallics and metallics will deteriorate the feel thru the pedal.

[MrDobin]

Sounds good. I hope to do this all one weekend at a time. Especially since being a first time replacement with a master cylinder I wanna take my time and be precise.

[Krashed989]

Remember that air floats up. Don't go bleeding the lines at the wheels after you change the master cylinder; you'll be there forever with no success. Just bleed the master by loosening the lines going to it (acting like the connection is a bleeder screw basically). It helps to tap the lines/calipers/whatever you're bleeding with the end of a screwdriver or something to dislodge air bubbles that may be stuck to the walls.

[MrDobin]

Yea. Figured that when I bled them a Tad. Today. Not suRe what difference it makes though. Air is air. The plunger obviously needs repair or just a totally bed cylinder.

[Ranger]

You should also bench bleed it before installing it. There should be directions with it.

[carnut]

I've learned having owned more than 2 Eldos of this era to make sure the rotors are surfaced when changing pads. The rears especially tend to glaze because of weak gripping of the caliper. The condition of the rotor surface has alot to do with brake pedal feel.

[MrDobin]

So just noticed this. Already planning on new parts on soon but made me curious. The rear right brake is moving maybe a half centimeter I think. When I begin breaking I can't start feeling the little bend in the rotar and then it seems to ease off. The rotars are gonna be swapped and the calipers. My puzzlement is how is one side engaging so slightly and the other not at all?. Seems odd.

[carnut]

Not odd at all. The park brake adjusters do sieze which would cause uneven gripping. Remove the park brake cable from both rear calipers then, by hand move the park brake lever forward. You will notice that one lever will move forward more than the other. That means that the one moving more forward is siezed more than the other. Normally when the park brake levers work correctly they will only move forward about 3/4 inch before the pads grip the rotor surface.

[MrDobin]

Ah gotcha. Helps validate my buying new rotors and loaded calipers then. Good deal

[MrDobin]

So. A much delayed update but this was worth noting because the mechanics of 30 years and 60 years total were baffled till they found the issue.

Proportioning valve.

It was locked in place and so my rears were not at all working. They put new pads in and calipers to the front and then discovered the lovely issue. Luckily overnighted a part in from Denver.... dont know the cost on that but w/e. Car back tomorrow so cheers. Thanks for the input before all.

[carnut]

Glad they found it. Keep in mind that the valve only addresses the hydrallic issue. Post back that, in fact, the parking brakes do hold the car in gear.

[MrDobin]

Will do. It was amusing though annoying to watch the mechanic bleed the rears and he got maybe 2 seconds of fluid haha.

[MrDobin]

So final deal:
Shop replaced from calipers and pads, as I requested. Also added matching tires to rear for fully symmetric look so the car is not riding white in back and plain black tires in front. They also as I said shipped in a new proportioing valve which we believed was the reason the rear brakes eventually just rusted and seized. Glad its all good now.

The bump in the road which ended up explaining the brake light, lack of park brake, and non existent rear brakes. ... as I figured and you all helped clarify, they were seized. The guys spent all day disassembling them and lubing them all up for full function. SO, it brakes like a dream now and no more annoying light on dash. Side note of amusement, the white walls that were on the car(rear) were the incorrect height. Explains a few annoying points i noticed prior haha. Thanks again all for the aid.