Over the weekend I was working on the brakes on the '87 GT that we just purchased that had been sitting for 4 or 5 years. My plan was to flush out the old brake fluid with new and replace all of the pads. I use a hand held vacuum bleeder (MityVac), to suck the fluid out through the bleeder valves - something I have used successfully for years on all sorts of different vehicles). I started off on the right rear and could barely get any fluid to flow. The bleeder valve was fine. I eventually got enough to flow through to bleed the lines but it remained very slow. I assumed that the brake hose was swelled on the inside and that was restricting flow, it also looked like that brake wasn't doing much braking. The pads looked good and since I needed to replace the hose I didn't bother to put the new pads on. Since I had that side jacked up I went and did the right front, I had no problems getting the fluid to flow and it was easy to bleed. I pulled the pads off and compared them to the new ones and discovered that the existing pads were basically brand new. The disc also was basically new and didn't show any wear, so I put the existing pads back on. I went over to the left rear and couldn't get the fluid to flow at all, but the pads and disc were basically new. Then I went to the left front and again didn't have any trouble bleeding it. I'm planning on ordering new rear brake hoses (since of course nobody had them in stock) but before I do I just wanted to make sure there isn't some sort of proportioning valve or something else preventing me from vacuum bleeding the rear brakes (since I had trouble with both rear brakes and neither front brake). Does anybody know? On the other hand I was pleased to find basically new pads and discs all the way around - not what I expected on a 25 year old car! Even the bleeder valves all unscrewed easily!
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09:05 AM
PFF
System Bot
FieroJam Member
Posts: 1118 From: Zephyrhills, FL Registered: Feb 2008
The 87 I bought last December had a similar issue with the rear brakes having very weak flow and it ended up being the master cylinder that needed to be replaced. As far as I know there is no reason that you should not be able to vacuum bleed the brakes.
Rear brake can be a bit slower that front. Rear has MC valve and prop valve to get fluid thru... MityVac should work if the bleeders are sealing the bleeder holes.
Likely need crush washers on banjo bolts.
Get DOT4 fluid. Has higher Wet Boil.
See my cave, brake section. Brake service rear brake fluid
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
If I was you I would replace all the brake hoses. Mine did the same thing and later after I got it on the road and a couple hard braking stops the front two hoses collaped on me. Thanks Lonnie
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10:10 AM
Lambo nut Member
Posts: 4442 From: Centralia,Missouri. USA Registered: Sep 2003
When you bleed them the next time, start with the left rear, then right rear, right front, then finally left front.
Kevin, I've noted time and time again here that people bleed the brakes on a Fiero in the wrong order. Even people who realize that there is a proper sequence to follow (farthest to closest) often get it wrong. I suspect it's because they've never checked the routing that the brake lines take in a Fiero and noticed that the caliper farthest from the brake reservoir is (as you've mentioned) the left rear one.
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03:01 PM
hzl6cm Member
Posts: 51 From: Odessa, Missouri, USA Registered: May 2012
This is what it says in the factory service manual that I downloaded:
4. If it is necessary to bleed all of the calipers, the following conventional sequence should be followed: a. right rear b. left rear c. right front d. left front
That is why I started with the right rear. Though I have found that with the vacuum bleeder it doesn't seem to be as sensative to order as when you are manually doing it by pumping the pedal. Especially in this case I was doing it more to replace the fluid instead of thinking there was air in the system.
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03:26 PM
Patrick Member
Posts: 37501 From: Vancouver, British Columbia, Canada Registered: Apr 99
This is what it says in the factory service manual that I downloaded:
4. If it is necessary to bleed all of the calipers, the following conventional sequence should be followed:
a. right rear b. left rear c. right front d. left front
Well, what can I say. It looks to me like that's a misprint in the manual. The rear brake lines in a Fiero are not arranged in a "conventional" manner.
quote
Originally posted by hzl6cm:
Though I have found that with the vacuum bleeder it doesn't seem to be as sensative to order as when you are manually doing it by pumping the pedal. Especially in this case I was doing it more to replace the fluid instead of thinking there was air in the system.
I'm no expert, but I've found the best way by far to flush and/or bleed brakes (and hydraulic clutch systems) is to use a power bleeder. They use air pressure to push the fluid through the lines. Works fantastic.
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03:53 PM
rmcmsw Member
Posts: 102 From: Kechi, KS, USA Registered: Aug 2001
Brakes: At 177,000 miles I thought it was time to re-build the brakes. I picked the Lebaron setup with Camaro and Cadillac calipers; had the rotors drilled and slotted. The install was fairly straight forward and then it came time to bleed the system. I could never get the rears to bleed properly. Re-built the proportioning valve, changed all the brake lines to new s/s ones, put on a new brake booster, of course the recommended master cylinder and still no bleed to the rears. Tried bleeding the old fashion way (two people, one to pump, the other open and close the valve), even speed bleeders and no luck. So I took it to the local GM dealer and after $300 + they gave the car back to me and said they couldn’t do it either. So I took the car to The Brake Shop in Wichita, Kansas. They’ve been around since the 1920s. It took longer for them to raise the car and take the wheels off than it did for them to bleed the whole system. POWER BLEEDING! Just like described in section 5-9 and 5-10 of the 86 Fiero service manual. Why the GM dealership didn’t do this I’ll never know, but I do know, I’m never going back to one. The car stops extremely well. No complaints.
I used to have a powerbleed setup for British cars (my MGB and TR6) that utilized tire pressure, of course when I had a bad MC it puked the whole reservoir worth of fluid on to my floor (the MCs were mounted above the footwell in the MGB). I have found the vacuum bleeder with the hand pump to work as well as a power bleeder, just a little slower, since it is the reverse of the process. I've used it successfully on everything from my Z06 to my kart. I've flushed the brake fluid from a lot of late model cars with it, it doesn't matter if they have regular or anti-lock brakes. I'll let you know how it goes with the new hoses.
------------------ 1987 Fiero GT for the kids to autocross (automatic transmission) 1982 Camaro CP autocross car 1970 Corvette convertible (toy, 350, 4-speed) 2004 Corvette Z06, semi-daily driver
The problem with vacuum bleeding is that when you crack the bleeder valve you provide a vacuum leak that can be easier to pull air from than through the rest of the system. While the order at which you bleed is a good idea it’s not critical and I don’t think is your problem. Pressure bleeding is a good rout to go but keep in mind that using the MC is also pressure bleeding. YOU MUST BE CAREFUL when using the MC! Old MC’s will build up a layer of corrosion inside the bore where the seals don’t normally ride so if you let the pedal move further down than normal it will move the seals past this corrosion and damage them (this sometimes doesn’t show up for a few weeks). If you use the MC, don’t let the pedal travel more than ½” or so and be prepared to replace it. If you don’t have access to a pressure bleeder sometimes replacing the MC is the only way to get a solid pedal again.
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09:09 PM
May 8th, 2012
85 SE VIN 9 Member
Posts: 690 From: Harwood Heights, IL, USA Registered: Apr 2010
firejo24 I wish you'd mentioned that before I tried the pedal after allowing air in the system somehow! Still haven't been able to get a bleeder open so still don't know, but it has got me worried about the MC now.
On topic: I've read a lot of threads about problems with rear brakes not bleeding/working/releasing and the problem always seems to be the hoses, specifically internal blockage or collapse.
I did a lot of shopping for hoses also. I've come to the conclusion that you might as well resign yourself to getting cheap Chinese junk because when you try to insist on something better they can't order it or can't get them. I had the best luck with Advance. They were able to order even the right rear and get it within a day or two - and for the best price. All the hoses I got came with two copper crush washers and other hardware as well.
By the way - I would stay away from the stainless steel braided hoses. I also got those, but then read a post, actually on a Jaguar site, that pointed out they're not necessarily any better than conventional and in fact may be worse because they're all the same and difficult to route and keep from twisting. The Ocelot set from TFS has banjo bolt connections that look like wedding rings rather than the big slab of metal on the conventional hoses.
Also, if you get all the hoses, note the part numbers relative to the wheel they go to and take pictures of each wheel before taking the old ones off - they're all different and have more than one application so there is no indication which is which on the box or hose.
