1G Is my proportioning valve upside down?

[DJ23GSX]

Long story short my brakes have never been amazing no matter what I've tried or replaced. I happened to come across a pic on the JNZ website that lists what ports are for what lines and it would appear mine is upside down according to that pic. https://jnztuning.com/product/oem-pr...d-big-brakes/#

Here is mine(non abs). Which is correct? Even if it were upside down would that make my brakes feel pretty awful?

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[AWD-Tony]

It’s on correctly. What do you mean by they feel aweful?

 

[DJ23GSX]

They just don't ever feel like they have a lot of bite. I need to push the pedal down quite far too stop quickly. Hell I don't even think they would lock up the front tires if I stood on them. It's been like that since I got it. I've replaced just about everything brake related over the years and nothing seems to feel that good. I've got EBC blue stuff pads on there now with good rotors (forgot what brand but I don't buy cheap stuff). The best description I can probably give is that mine alway feel like they are faded like they are over heated.

 

[AWD-Tony]

Does your pedal feel hard? Does it feel the same when the engine is running vs engine off? Have you looked into the booster?

 

[dwb]

Yup you're good. Here's my non abs.

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[steve]

Did you ever fix this? https://www.dsmtuners.com/threads/brake-pedal-goes-to-floor-after-sitting.489886

 

[DJ23GSX]

Does your pedal feel hard? Does it feel the same when the engine is running vs engine off? Have you looked into the booster?

Pedal feels good. It's not hard. The pedal gets real firm when I pump it with the car off then sucks back down after I start it. Not sure of any other ways to test the booster.

Did you ever fix this? https://www.dsmtuners.com/threads/brake-pedal-goes-to-floor-after-sitting.489886

Yes a new OEM master.


So just to confirm the JNZ pic is wrong? My top ports (inline with the bolt hole) are running to the rear and the bottom to the fronts. According to the JNZ pic the ports next to the bolt hole are for the fronts.

 

[Mech Addict]

The JNZ photo is simply showing that part for sale, not as an installation diagram. So I wouldn’t call it “wrong” as far as that goes. Even with the valve mounted properly, the lines could be connected wrong, but you would find your rear brakes locking up when you stomp them.
The prop valve actually just restricts pressure to the rears as more pressure goes to the fronts. Poor breaking could be from old fluid, air in lines, leaking booster (Or failed check valve on vacuum line for turbos), internally worn M.C. Or calipers, worn pads & rotors...
From what I’ve read over the years, some of the higher end racing pads are more tolerant of repeated hard breaking, but give up some feel and bite when used for regular street driving.

 

[DJ23GSX]

Thanks for your reply Mech. I've tried a bunch of different pads over the years and nothing really had that nice grabby bite I get in my newer vehicles. Maybe I'm just expecting a little too much out of them. I just put it back on the road so the more I drive it the more I'll dig into the brakes and try to figure something out.

 

[AWD-Tony]

Mine is a stock setup except for hawk pads and I feel they’re just as good as other non-modified system.
Was the master bench bled?
Have you used bottle method to bleed the calipers? If so, was it moving a decent amount of fluid?
I had decent amount of brake fluid in my booster when I got my car but I don’t recall my brakes feeling any worse. You can use a long zip tie to put down the booster port like a dipstick to check that. Just curl the end to get it down there. Not sure if it’ll help but worth checking. I’d also check the check valve to make sure that’s in working order.

 

[DJ23GSX]

I did bench bleed the new master. I've checked the booster line check valve in the past but I'll check it out again. I've bleed the entire system at least half a dozen times. They do push a lot of fluid. I don't loose any brake fluid over time either. I did notice yesterday that I've got old rubber lines in the front. I was certain I had SS lines on it before not sure what's up with that.

I've had this DSM for 10 years and 2 others before it's hard to keep track of all the stuff I've done over the years

Since you guys are being so helpful I guess I can try and explain my brakes a little better.
My pedal feels good. Not too soft not too hard. I'd say about 1/4 way down I can feel the brakes just starting to grab. By about 1/2 way down they start slowing the car down but after that it doesn't feel like I have much more braking power left no matter much farther I push the pedal. I would think with that much more pedal travel I'd have a lot more braking power left. My pedal doesn't go all the way to the floor either under hard braking.

 

[AWD-Tony]

Are the rotors new? If not measure them to make sure they’re still within spec. Idk what that is but I’m sure you can find it. I’d also remove the caliper bracket and make sure the pads move freely in the bracket. I actually had to remove some material off one of the rear caliper brackets because the pad was getting hung up. Check the pads for even wear and rotors where the pads make contact.

Does the car pull in one direction when you brake hard?

 

[DSMPT]

Have you inspected brake rotor's condition? Thickness, warping cracks etc.

Edit: Oh sorry, Tony posted while I was writing.

 

[DJ23GSX]

Car doesn't pull at all under hard braking. Pads have tons of meat left rotors might have a few thousand miles on them if that but the car does sit for long periods of time and they rust over. They clean right up after driving a few miles. Last brake job I did was new pads and rotors and they still felt pretty underwhelming.

 

[AWD-Tony]

If/when you install hard lines, remove the calipers and make sure the piston move in and out smoothly & evenly. I suspect something is getting hung up whether that's the pads or caliper piston. Also make sure the slide pins move freely and they're lubed with brake lube.

 

[DJ23GSX]

Does anyone sell just front SS lines? Seems like all our popular DSM venders only sell them in full kits front and rear.

 

[HaveBlue83]

Currently having this issue after a full 4 wheel brake lines, calipers pads rotors and bleed.

Car off: brake pedal is firm as a rock. Turn the car on, goes down, braking is terrible. I def cannot drive the car like this. Before the old brakes didn't feel weird. Car sat for years but I could hold it on the trailer without worry. But the car was off.

Lines look ok. Why is the pedal sinking upon start? What makes the vacume booster ruin the pedal feels?

 

[FIBA M - EC17PSE]

Currently having this issue after a full 4 wheel brake lines, calipers pads rotors and bleed.

Car off: brake pedal is firm as a rock. Turn the car on, goes down, braking is terrible. I def cannot drive the car like this. Before the old brakes didn't feel weird. Car sat for years but I could hold it on the trailer without worry. But the car was off.

Lines look ok. Why is the pedal sinking upon start? What makes the vacume booster ruin the pedal feels?

Did you remove the booster check valve in the line at any point? This can cause some weird issues also. Alot worse when driving and in boost as you have very little brakes then

 

[HaveBlue83]

Did you remove the booster check valve in the line at any point? This can cause some weird issues also. Alot worse when driving and in boost as you have very little brakes then

No idea where that even is

I took it for a drive and I'm going to rebleed the front calipers and bed the brakes some more, it's not undreiveable

 

[dwb]

The check valve is molded inside the vacuum line that runs between the brake booster and intake manifold.

 

[HaveBlue83]

The check valve is molded inside the vacuum line that runs between the brake booster and intake manifold.

Hmmmmm, well this is a swap car to a 6 bolt and the vacume line was modded a bit...I wonder if they removed it. I know what you mean now. Ok I'll look and if it's missing that's prolly why!