It was a very exciting weekend and also a very frustrating weekend (sorry for the long explanation):

Got my new rims, the classic Mille Miglia Evo 5s in 17x8, and at the same time I put on Porterfield R4-S pads, front and back. Broaner helped me out big time with the brakes on Saturday. I don't know exactly how we bled the lines (step in here, Broaner) but we didn't do it properly the first time. I had a very mushy pedal and almost no braking power. I didn't realize that the lines weren't properly bled, so on Sunday morning I went out to bed the pads. I must have done 20+ 60-10 MPH stops with little improvement. There wasn't enough braking force to slow the car down fast at all. I noticed that the left front and right rear brakes were hot but the other two were not... There was also lots of crap all over the left front wheel, and the pads were WHITE from getting very hot and possibly bursting into flames (noticed this later, otherwise I wouldn't have done 20+ hard stops!). Metal from the rotor all over the surface of the pad. Turned out the bolt for one of the pistons was loose...oops. So that pad was being forced against the rotor and probably had been doing most of the braking that morning.

Anyway, we fixed that (although there is crap on the rotor surface and maybe some grooves also, so I will have to get a new rotor soon) and re-bled the lines in the proper order (right rear, left rear, right front, left front). There was definitely air in some of the lines. I think we did it properly this time, but we only bled until steady fluid was coming out. In other words, we didn't totally bleed the lines. So I started the car up and the pedal felt better, but still too mushy. Braking force was better, but still only about 50%. We went out to try bedding again without much luck. We did enjoy seeing my left front rotor glowing orange, blacksmith-style!

We are puzzled. It seems to me that this has to be a fluid issue, but things didn't get much better after re-bleeding. At this point, I guess it wouldn't hurt to totally bleed the lines again (didn't want to waste all that brake fluid at the time). Note that we did not use brake shims and the rotors are the ones that came with the car when I bought it in February. Braking with OEM pads was fine before I switched. Anybody have ideas?

 

Do you have an pictures of the install? If your lines are twisted that could cause trouble. Also you should check out haynes..
Proph

 

We did refer to the FSM a few times but didn't follow it step-by-step. Good idea about twisted lines, although they're pretty beefy lines and I don't envision them twisting easily. Besides, even if one line was twisted it would seem like the other three brakes would be normal.

I sincerely hope that the loose bolt on the one piston didn't fxck things up royally...

 

bump!!!!!!!!!!!

 

holy crap...if you're stopping until the rotor is glowing then i'm sure the brake fluid is over heating. what type/kind of brake fluid are u using? is it or was it from a new sealed container?

did you clean everything before you pushed the piston back in? maybe you have a sized caliper. did you grease the sliding pins?

so many thing could've gone wrong here.

personally i've used porterfields on my cars and friend's cars and everyone expressed much better stopping and reduce fading. only downside is the dusting.

 

Well to me if only one of the brakes is glowing red then that means that you are having unequal braking which isn't good. I would personally make sure all of your pins are moving freely and make sure you are bleeding it correctly.

Unless you have a vacuum to pull it out. (on my list of things I want to get) It really is a two person job one person pumps other person watches and just make sure the your partner on the brake keeps the pressure down while you close the valve otherwise it will suck air back in and you just ruined the bleed. Also make sure the fluid doesn't go below the line ever otherwise you are adding air into the system at the reservoir.

I have had porterfields on now for about 8 months and they are simply amazing other then the dusting. I can live with that though becuase they have saved me at least 3 times. Two of those times were on the highway where things came to a complete stop and my car went down from 80 to zero very quickly. Please make sure all 4 brakes are working before bedding otherwise you will warp and maybe ruin the pads due to uneven braking.

 

Intel, we did the bleed correctly. Valve open, pedal down, vale closed, pedal up, repeat a few times. We kept the brake fluid near the MAX fill line in the reservoir. It's Valvoline DOT3- & DOT4-compliant brake fluid.

Thanks both for the seized caliper/pins suggestion. We will have to check that. We did NOT grease OR clean anything, but I don't see how any of the calipers would start malfunctioning just by replacing the pads. Everything was working fine before and nothing looked particularly dirty. (I guess I'm sounding pretty naive now, LOL.) I was planning on doing a complete brake overhaul next time around, but maybe I should now. Is there special brake grease I should get or any kind of OEM kit?

 

I did check the Motorvate write-up before doing the pads, but I didn't think that I would need to do all those things just to replace the pads. This sounds familiar, though:

"To remove the pin that the caliper slides on as the brake pads wear, you can gently pull them out. If these stick in any way, the caliper will not be able to slide to (brakes on) or away (brakes off) from the rotor. This can lead to the brake pad dragging, and this causes the pad to wear very rapidly. In one case I saw a car with the rotor glowing red!"

So I'll have to check the caliper pins and probably grease them. Will that do it, or should I buy the Brake Hardware Kits and/or Caliper Seal Kits (http://www.courtesyparts.com/A32_brakes.html)? I'd rather not replace everything now if I don't have to.

But would one sticking caliper pin cause the continued mushy pedal feel?

 

ok here's the thing about bleeding brakes. very tedious and hard job if you DON'T have speedbleeders. I have them and they are awesome i bleed the brakes on my car in 5 minutes (excluding the amount of time to raise the car and remove the tires.)

instead of having two people you only need to connect the hose, open the valve, press the brake pedal a few times (or however many it takes to get the old fluid out) then go check the fluid in the hose, then close the valve, you're done.

www.speedbleeder.com

and they only cost $8 each.
great for anybody who goes to the track, runs autox or drives aggressively on the street.


I'm planning to switch to porterfields

where did you buy them? how much?

 

if u had a pedal before...and now you dont..and you opened your lines..99% chance its air in the line...u dont need to bleed the lines empty...3 slow pumps and hold down...if u still have no pedal do it again and make sure u keep re-adding brake flud ias you go

 

If your pedal was fine (not "mushy") before changing the pads, why did you feel the need to bleed them?
My FSM (for a '98) lists the bleeding order as right rear, left front, left rear, right front.
Your helper should be fully depressing the pedal several times before you open the valve and should be maintaining pressure when you open the valve. Valve must be closed before the pedal reaches the floor. You repeat this several times until just straight fluid comes out and then move onto the next caliper.
I have been using the two person method for a little over 20 years now. If both people know what they are doing, it works great. If the two of you are not in sync, you will just end up drawing more air and other contaminants into the system.
I recently purchased a hand vacuum pump for flushing and bleeding my braking system. It is a one person deal but I find it pretty tedious. Takes me about 30 minutes to flush a quart of new brake fluid through the system.

Speed bleeders are OK, but you still have the small volume of air between the bleeder screw and the check valve that can return to the caliper when you release the brake pedal.

 

Thanks, eng92, that could be part of the problem.

 

you bleed the brakes to remove moisture and dirt that settles at the lowest point of the brakes....your calipers. brake fluid is hydroscopic...so it'll asorb water from the air. when doing a brake job fresh brake fluid should be used every time. that stuff sitting on your shelf that you opened 3 years ago is pretty much junk...toss it out.

2 person method always worked...but it's still a 2 person job. hence the new technology. the vacume pump u is ok...eventually u get tired. i now used a tank that pulls a vacume by compressed air.

how does the air get trapped in the speed bleeder? it's a check valve. it opens and fluid gets through when you push the pedal...it closes the second you lift your foot up. have you used these before and were dissatisfied with the results or are you just speculating? try the product before commenting.

 

I have used the product before (They were a gift). They are now sitting in a parts bin collecting dust in my garage. I have been designing hydraulic systems for over 10 years now. All valves leak to a certain extent depending upon pressure differential, valve design and level of contamination in the system. In a well maintained braking system (ie. flushed annually) there should be no problem with them.
My concern is that the smallest of particles, dirt, rust etc is enough to hold any check valve off its seat and allow air or other contaminants to be drawn back in to the sytem when you release the brake pedal. I bought the hand vacuum pump so I could witness the direction of fluid flow, air bubbles and quality (ie. cleanliness).

 

I think that the other possible problem is that you pushed the piston too far back in, and it seized up. I just changed out my front calipers, and I had to bleed the whole system. I also installed steel brakelines, and I am happy as can be about their performance. The only thing I can think of is that you damaged the caliper somehow. When changing the pads, you shouldn't have had to bleed the brakes, but so be it, you can't go back and do it over. just check out the caliper, and see if it is working. Jack your call up, and press the brakes to see if the wheels are locked up enough that you can't spin them. Sounds like something is wrong, but you need to move forward. Good luck, if you need new calipers, I'll send you my old ones cheap.

 

Is flushing the brake lines different from bleeding? Sounds like it. Since I don't have service records from the previous owner, maybe I should just take my Max to a brake shop to get it flushed and refilled.

 

Okay guys, many things. 1. We bleed the system because the bleeder valve had to be opened to get the piston in all the way. 2. We were bleeding wrongly. Every show, magazing and book that I've ever seen or read has stated that brakes are bleed in the order of distance they are from the MC. Apparently the Max is different. We will do it againg tomorrow. 3. There is a possibility that air was sucked in through the resevoir because at one point the fluid was below the line briefly. 4. The wheel do not need to be removed to bleed the system. The bleeder valves are easily accessible if you get on your back and reach up. 5. All of the discs are getting hot which inturn leads me to believe that all the pads are touching the the disc just a different intensity. The FL is conntacting the disc very harshly and doing 85% of the braking. The RR is doind about 10% of the work and the other two are barely coming up with the last 5% between them. Its got to be related to bleeding. 6. The lines aren't twisted. First of all, they aren't long enough to allow the caliper to bolt on if they were twisted and if they were they would snap the moment you turned the wheel to lock.

Thanks for all the suggestions guys. We'll deal with this tomorrow and hopefully it will be solved.

 

Yeah, we'll bleed the sucker dry tomorrow for good measure!

Broaner, this is interesting: I'm looking at the FSM and here are all the steps for rear pad replacement:

So you don't need to bleed to change pads. (Just be sure to change your pad after you bleed if it's that time of month.)




This is why my L front and R rear pads were hot but not the other two. The L front and R rear are on the primary line and the other two brakes are on the secondary line. The two lines seem to be largely independent of each other, passing through the "dual proportioning valve" which allows some crossover but not too much. So this is why the bleeding order is not just whichever is farthest from the master cylinder first.

I bet I have a lot more air in the secondary line than the primary. Only 50% or so braking power, pedal still feels mushy, but enough power on the left front brake to turn the rotor orange. That's my theory.

BTW, this is an example of good design: if one of the main two lines fails, you won't loose your entire left or entire right side brakes; instead, you'll loose one front and the back on the opposite side, which means the car will be more balance and safer to limp home.


Of course, I'm sure every car manufacturer does it this way, but still, gotta love Nissan haha.

 

Every car manufacturer doesn't do it like this. I've never heard of another car with a brake setup like this.

 

does being an engineer mean that you can work on a car? are you somehow ASE certified at the same time being an engineer?

please stop picking on the spelling...you know exactly what i was referring to.

flush and bleed...so you're saying that if you bleed your brake fluid you're not removing any dirt or moisture in the fluid?...not one tiny bit? are you professional engineers that **** 24/7?

hey i guess your right/left hand is stronger than mine when pumping that hand pump. i have my air compressor do the work for me. if the pump works for you...then so be it.

let me just say...for the "average user" speed bleeders are satisfactory in removing air and whatever in the brake fluid/lines. unless you're an professional engineer then go and buy that mitivac pump and pump the fluid out yourself.

i'm sure you're good at what you do...but doing what you do doesn't make you qualify to work on a car...does it? now if you can keep your ego in check and actually be open minded about the discussion...all i asked was how do you think air would get trapped in the speedbleeder...that's it. the rest was just info for the orig poster. i didn't ask for your entire life history or career. you don't know what i do...you don't know my experience. i might be the guy that signs your check...you don't know that...don't assume.

you have 14 posts here...you're 37 yrs old...how about growing up a little instead of getting all bent out of shape about a question/discussion on a forum?

 

Not to be really picky or anything of what you guys did. But there is no reason to have to bleed when you push back in the pistons. The fluid just goes back to the reservoir and you make sure you open that first and then compress the pistons. The only reason why you should ever have to bleed other then if you just want to is if you had to replace a caliper. Like when I had to replace both rear calipers becuase they were basically stuck then I had to bleed but otherwise there is no need to open the valves if you are just putting pads in.

 

Wow, Dan, you're really living up to your "Bitter Moderator" title!

Intel: thanks, now I know.

 

Well the truth is the truth. Ego trippin' doesn't show that someone knows what they are talking about or being able to perform the task at hand.

 

What's really important is that we've established who is smarter than who.

 

Brake systems are one of the most important things on the car and they often go over looked. At least you know you have a problem. Try bleeding the poor braking wheels and check the slide pins just to be safe. I had a rusted up pin and that caused the caliper to seize. Good luck you 2.

 

SUCCESS!

Here's what we did:

1. Checked that brake fluid reservoir was at MAX line.
2. Disconnected battery negative terminal (for ABS)
3. Pumped brake pedal a bunch of times with Broaner at the valve. Then I said "go" as I started slowly but steadily pushing the pedal down until it was almost at the bottom, where I said "stop". He opened the valve when I said "go" and closed it when I said "stop" (duh).
4. Did this for each of the four brakes, starting with R Rear, then L Front, then L Rear, then R Front. There was quite a lot of air still in the secondary line (especially L Rear).
5. Throughout the procedure, kept brake fluid near the MAX line in the reservoir.
6. Put everything back and drove off to bed the pads again.

Now I can drive again! Whew.... Thanks everyone for the tips. Some time next year I'm going to do a complete brake system overhaul. And this weekend I'm going to have a look at the caliper pins to make sure there are no problems there.

 

BTW the combination of the Porterfields and the 235 Kumhos stops the car in a hurry.

 

VQuick - Glad to hear that your brake problem is now resolved. I would also like to apologize for cluttering up your thread with non-contributory information.

 

VQuick i'm glad everything worked out for the better, but you still didn't answer my questions.


Where did you buy the Porterfields? and how much were they?

how dod you like the pads compared to what you had before (now that your brakes are fixed)

thanks

 

Tom, you still have your eyeballs in their sockets? How did it go? I told you it felt insane once they started grabbing.

Intel, when pushing the piston back in I always found it much easier to get it in with the bleeder open. I don't have the proper tool for the rear piston and twisting with a pair of needlenose is really difficult. With the bleeder closed I have to push all that fluid back through the system with a pair of pliers that is barely getting purchase in the little notches. I know that bleeding is not required but it makes things easier.

 

eh I just rented the thing from autozone for free.. unfortunately it didnt make much difference since the rears were shot.

Also yeah once those porterfields start grabbing it is amazing.. has saved me more then once and is probably one of the better things I did on my car as far as safety is concerned. Dust a bit though but hey who cares.

 

there are alot of other vehicles set up like this....but a ****load without it too

 

I bought them from their website. The list prices are AP430 $89.00 & AP540 $69.00 but I e-mailed them asking for an Org discount and they told me:

Fronts AP 430 R4-S $71.00
Rears AP 540 R4-S $55.00
Shipping appx $12.50

So that's what I paid. Your shipping price might be more or less.

I haven't had much time to test the brakes, other than bedding them in yesterday, but they definitely grab. I haven't tried to see how much it takes to get them to fade, but I've heard they're significantly better than stock pads in that respect.