Sierra :: 1989 GMC - Brake Pressure Fading / Goes Completely To The Floor
Dec 3, 2012
I have an '89 GMC Sierra which has the standard rear wheel anti-lock brakes offered that year and a vacuum booster. It has about 180,000 mi. on it. I have a problem with the brake pedal fading to where it goes completely to the floor. This happens whether the engine is running or not. The brake warning light is not on (but is operable), there is no air in the lines, and their are no external leaks. The resevoir has stayed at full level. I rebuilt the master cylinder and the bore looked great as did the seals, but I installed the rebuild kit anyway.
There has been no change in performance. Can this be a problem with the isolation/dump valve assembly leaking internally. I would think that would cause the warning light to come on. The i/d valve is a costly part to replace and I hate to experiment on such a solution without some confidence in the source of the problem. The GM Service Manual troublshooting indicates air or internal master cylinder leakage is the culprit, and indicates the light would come on for any i/d valve problems.
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MY 2005 chevy silverado 2500 developed brake problems. The power steering pump, master cylinder, and Hydro static something or other has bee replaced.Now the pedal fades with constant pressure. The shop tells me this is ok but today at at a downward sloping boat ramp with the pedal at the floor, it was very scary.Before the parts were replaced this problem did not exist.
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M friend with his 98 gmc. When stopping the breaks are normal until getting slow then the abs motor comes on and the break pedal sinks to the floor. The truck stops but the abs motor runs constant until you release the pedal. This is happening on dry roads. What is there to check before condemning the abs module?
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I am working on a e-150 van, 2005. the brake pedal fades to almost the floor with little pressure on it. I just replaced the master cylinder, bled the entire system, and it STILL fades to the floor. driving, or in park. engine running. 4 wheel disc, 4 wheel abs...
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My 1989 GMC k1500 step side makes a buzzing noise when i run the heater, when i turn it up the noise gets louder, whats causing this and how do i fix it?
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I have a problem about which the mechanics I have asked are baffled: In cool, cloudy or sunny weather, my brakes and break-pedal pressure are fine (the mechanics have said I have good fluid, brakes, etc.--they can find nothing wrong--and, of course, it never has a problem when they test-drive my car). However, when the weather warms up and it's a bright, sunny day, my brake pedal loses pressure and slowly sinks to the floor--a dangerous thing at intersections. There's slight pressure if I pump the pedal constantly while at a light; but, without pumping, the pedal immediately sinks to the floor.
This is a real problem, because this problem always occurs right when mechanics are not near or not open for business--and none I've talked to have ever heard of such a problem. The bright, hot sun's affect seems to be key, because if it's 80 degrees outside and cloudy, I don't have the issue--but, then again, I don't usually run the air conditioner if it's cloudy. As such, I'm not positive; but, this may be tied to when I turn on the air conditioner--as though the two share the same vacuum system.
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2001 F-350 / 7.3L / 147K ... What are some symptoms of the master cylinder going out? And is there a such thing as a rebuild kit anymore? The pedal has been getting spongier & spongier over the past months. Truck still stops O.K. but you have to brake earlier than I used to. Pedal can go almost to the floor. Pedal continues to go to floor as pressure is applied. Does not go to floor though.
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Last night transmission in my beloved '89 Caprice Wagon let go, it slips completely in all the forward gears. I was coming down a long hill using low gear for several minutes and when I put it back into OD at the bottom it seemed to skip a little but it was still making power well enough. I got off the freeway at my exit and stopped at a red light, when the light changed I was revving high but barely creeping through the intersection. I pulled over and this is what I figured out:-All the forward gears make essentially no power any more.-Reverse seems to work normally.-The fluid is at a normal level and not discolored or burnt smelling.
I don't know if this is related or just an amazing coincidence but the water pump also seems to have blown the gasket at the same time. I must have just happened within a few minutes of me pulling over because there was still a ton of coolant left and the temp was still in the normal range. I don't see how they're related but, like I said, the timing is too coincidental. Earlier this week but just a few miles ago I also topped the power steering fluid and oil.
It's a 200-R4 transmission, is it toast? Why does reverse work but all the forward gears slip completely? Is the water pump just a red herring? I did drive the rest of the way home in reverse.
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R logo on the brake caliper clip fading? Mine doesn't seem as "clear/clean cut like it should be, seems kind of faded....
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Noticed blue calipers losing their color? Specifically looking like they have a dull coat of wax on them that doesn't come off with normal washing.
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I drive a 1989 Toyota Camry LE with a V6 Engine. When I fill my gas tank, start the car, the fuel gauge pointer doesn't go completely into the "F" mark, see picture; I'll even wait after driving a few miles if the pointer will try to go past the "F" mark, but it won't. Could it be the gauge be faulty or the sending unit in the gas tank that's causing the gauge to read inaccurately?
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2005 VW Jetta: The brake indicator light came on in the dashboard. I took the car to the dealer, and they replaced the front brake pads. Indicator light is now off, but I drove away with a new problem: The pedal fades as it comes to a stop. I have to push almost to the floor to stay still. Sometimes the car drifts forward if I'm not consciously pushing down harder than usual on the pedal. The dealer took the car back for a few days, replaced the master cylinder, bled the lines and did not charge me. But the problem is still there. What went wrong?
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I recently purchased a mutt of truck, a 97' F150 heritage w/5.4 Triton motor, 1/2 ton 2WD short bed.
Having a brake issue, the pedal keeps fading. I noticed it first while sitting in traffic on a down hill grade. I am holding the pedal and notice it starts to creep down slowly, I pump it up and it firms up then starts collapsing again. So general logic says hydraulics are loosing pressure right?....No leaks anywhere, so it must MC tight?
I have replaced the master cylinder, brake booster, and both rear wheel cylinders. Long story short they all needed it, truck has 265K+ on the body with 95K on the motor. The only thing I did not do by standard is bleed the MC on the bench, I installed and long bled starting with the right rear working my from longest distance to shortest (wheel speaking). So when bleeding I did of course get air coming out because of the new parts but I still have the same fade issue.
I am confident there is no air in the lines, I have bleed a quart of brake fluid through just to be sure. I have read a lot about proportioning valves and ABS stuff.
I will try and get some vehicle specific photos and attach have hit a road block with this. I am leaning towards the ABS valve thingy mounted on the drivers fender that has four lines attached (2 in and 2 out). Other than that it comes down to hard lines which have no leaks.
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I just purchased a 91 sierra sle with the short bed. I am interested in buying a cap for it because the snap on tonneu cover is falling apart and id like a cap. Would caps from other full size short bed pickups work or does it have to be from a sierra/silverado?
Also i notice the oil pressure fluctuates from around 20 to 80 depending on if I am idle (20) to acceleration at 80, when driving it seems to go up and down to depending on the accelerator position. is this normal??
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When it's cold I can floor it and it'll go to 4K RPM.....When it warms up the oil pressure drops and then I can't push the motor over 1500 RPM. I overhauled it and used the old camshaft....I really don't want to get charged 80 bucks an hour for a mechanic to take 2 days to tell me it something I could have fixed myself.
1999 GMC Sierra 4.3 V6 "W"
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I have an 03 Sierra Half Ton when the engine is warm it runs fine but at cold start, half the time it doesn't have the fuel pressure to start, i have to turn the key a couple times to build it up. Idk if the fuel pump is weak for if it would be more the regulator. I started having this problem after i replaced the fuel pump. The fuel pressure gauge shows 50-55 lbs, but every now and then when its cold it will only jump to around 5 lbs (but this is only when the engine is cold... why?) What should i go after first? Regulator, new pump, Replace the fuel filter again?
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I have the code P0453 set and believe I need to replace the fuel tank pressure sensor. I have the part and want to know if this part can be replaced without removing the fuel tank. There is a video on youtube that shows replacing the part by lowering the tank with a transmission jack after the straps have been removed. Replacing the sensor by touch and feel maybe using mirrors to see what you are doing? It might be possible to cut a hole in the bed and patch it later but that seems pretty time consuming too.
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The brake lights on my 97 GMC Sierra are not working right. When you apply the brakes the lights come on when you first press the pedal but then they immediately go out. I'm thinking brake pedal switch. Any other possibilities I should look at?
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99 Suburban LS 4x4 with the 5.7 with 109k miles. My Suburban broke down on my wife a few weeks ago, figured out that one of the catalytic converters had a catastrophic failure and came apart internally. I cut the cat off so that I could drive it the 60 miles home to save on the tow charge.
Had the cat replaced today and now I'm blowing white smoke out the tailpipe like I'm 007 throwing a smoke screen. The smoke alternates from smelling really rich to smelling like oil (pre-burn).
The oil pressure gauge is reading at or below 20 PSI and randomly (usually while breaking or stopped) completely bottoms out. I know cluster gauges aren't known for their accuracy but I also know this isn't 'normal' behavior. I also hear noise from the engine (possibly valves sticking but could also be more of a knocking sound than a clicking one). The oil is full (actually a little too full) and it went from looking like brand new oil to jet black in less than 30 days. I talked with the rep at one of the 'big name' auto parts stores and they recommended trying a 20W50 weight oil for a couple of months. Stated they have a similar vehicle with the same motor and made the switch a few years ago and hasn't had a problem since. I plan to do an oil change this weekend, I also bought an oil pressure sending unit that I'll change out at the same time. Am I on the right track?
Also, and most likely unrelated, my coolant temp gauge is totally inoperative and is just bottomed out no matter how warm the engine is. The coolant hoses (supply and return) are warm/hot to the touch at running temp so I'm sure coolant is circulating. What's the easiest way to check whether that issue is the gauge itself, the thermostat, or the sending unit?
There are no codes that come up on my OBD II reader at the moment.
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2005 Sierra 4WD 1500 Crew Cab.
My 2005 Sierra, with only 42,000 miles on the odometer, has been stricken by the corroded brake lines syndrome. So far, only one line has burst - a line to the left front brake - spraying brake fluid all over the exhaust manifold and leaving me with rear brakes only. I'd like to know, before borrowing a car and heading off to the parts store for a generic length of pre-flared tubing, what the tubing diameter is (i.e. 1/4" or 6mm) and what the thread gauge on the fittings is.
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How to remove the front brakes pads and rotors on my GMC Sierra 2008 - 1500 - crew cab - 4X4.
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