Brake Booster Issue

[jco1971136]

Hi everyone. I'm having a problem with my brakes on my 88 Reliant 2.5. A month or so ago I was coming home from doing some laundry with my sister and the brake peddle went to the floor. I could still limp it back to her house, but when I checked the Master Cylinder it was bone dry. Once I got it back to my place and checked it out, it turned out that the Wheel Cylinder on the passenger side rear was shot. I replaced the Wheel Cylinder and the pads but I'm having trouble understanding how to bleed the brakes. I should also mention that I had a hissing noise whenever I pressed or held the brakes on, and I think that was a Brake Booster going south. I just tried to bleed the brakes and I get a VERY stiff peddle when the engine is off, but still almost no peddle when the engine is running. As I tried to bleed the brakes, there was quite a bit of air in the system. My question is this: If the Brake Booster is shot (not airtight) would it be sucking air in and could it somehow get into the hydraulic system and prevent me from successfully bleeding the brakes? Any help will be greatly appreciated. Thanks!

[Kwagon2]

Hi
Answer to your question ...in a word no....The brake booster is independent from the master cylinder , the hissing that you're hearing is due to wear in the pushrod seal at the rear of the brake booster. Bleeding the brakes should be no problem , however you must realize that the K cars used a split system that is not split front to rear as is accepted as the norm but its split diagonally across the car as in the left front works with the right rear etc. So...you need to bleed the right rear and then the left front. When bleeding ensure that the bleeding screws are always closed when allowing the brake pedal to return and its always a good idea to have the end of the bleeding hose that's attached to the screw submerged in fluid.
The stiff pedal is normal with the engine off as the booster is not providing any assist and you're pushing against the diaphragm etc.
Hope this helps....

[jco1971136]

Hi Kwagon, thanks for the quick response.

If I understand you correctly, I should bleed "both" Left Front "and" Right Rear, even thought I only replaced the Wheel Cylinder in Right Rear?

When I was doing it the other day with the one-man bleeder kit, I never got a solid tube full of fluid with no air, like it says in the instructions for the bleeding kit. I used about 1/2 of a quart bottle of Brake Fluid and I assumed that I should have replaced all the fluid in the line. Also the bottle that came with the bleeder kit is tiny, I had to stop several times to empty it into another bottle. It seemed like there was air getting in from somewhere else, even when I was using the kit correctly.

Do I need to replace the Booster since the pushrod seal is probably bad, or can I just replace the seal?

Sorry for all the questions, but I've never done this job before. I replaced the Power Steering Pump, did a complete flush and refill of the cooling system and the brake pads on the back. I like working on the car, but sometimes the processes baffle me. Even though it's 28 years old it only has 85,000 original miles, so I want to keep it going.

Thanks Again Kwagon

[Kwagon2]

Hi Again!
With regards to bleeding both the answer is yes , generally if you're quick like a bunny and all the planets are aligned
you can get away with just the one cylinder ...on K's I've never been that lucky so I've always done both ...right rear first then the left front. Something about the one man bleeder kits , with the suction gun you can pull air in past the bleeder screw itself , so you'll be bleeding the brakes forever and not get anywhere. For driveway/home garage jobs I've always rounded up an assistant (usually the wife) and we do the open/press/hold/close/release method using moderate pedal pressure. In the shop I always used a pressure bleeder at the master and that always did the trick.
With regard to the booster, if its causing a major vacuum leak where engine performance is affected ( engine will start to miss or run rough when the pedal is pressed) then I would consider replacement. If the vacuum leak did get bad enough, you could experience an engine stall on braking . Rebuilds are readily available (see Rock Auto) (I usually never bother with piece parts etc. the last brake booster repair kit I bought was for a '66 Dodge) Its easier and less hassle and cost effective to just get a rebuilt booster.
No need to apologize for the questions ... If I can help all the better....
If your K has only 85,000 original miles then I'd say its a youngster ...keep changing oil and looking after it ....I put close to a quarter of a million miles on an '83 2.2 and it still had more....

[jco1971136]

Hi again Kwagon.

Thanks for the info. I'll try to bleed both in a couple days, but we're expecting some snow tomorrow.

I don't know if all the planets will be aligned, that's never been in the cards for me, lol. I don't think the single cylinder bleeding is going to work. As far as "pulling air past the bleeder screw", I think that's what was happening, because there were times when I had almost a full tube full of fluid, but sure enough seconds later, there was more air coming out. First I thought I'd try to just let it gravity bleed since the rear of the car is somewhat lower then the front, but it seemed like it was taking forever to happen. I don't have the type with the gun, it's just a bottle with a plastic tube coming out of it. I'll try to round up a friend to use the 2 man method.

Another question: someone told me it might be possible to do a reverse-bleed by removing the cap on the master cylinder and leaving the valves on the wheels tight and pressing on the peddle to let the air escape through the master cylinder. What do you think about that?

I'm not having any engine issues, but I always wondered if there was a vacuum leak because the car has almost no "spunk". At times I think it doesn't even want to get out of its own way, but other then that it's been pretty good to me. I bought it in 2006 for $600.00 and put maybe $500.00 into it in total since then other then the inspections.

Thanks again my knowledgeable friend.

Merry Christmas

[Kwagon2]

Hi Again!
Merry Christmas to you as well!
Just so that we're clear on the bleeding procedure, you will be doing one cylinder at a time with all other bleeder screws closed, on "standard systems" you always start with the cylinder the furthest away from the master cylinder , with the K car its the same idea just keep in mind the diagonally connected design ....Fill the master cylinder to the top (if the little bladders have come out of the caps just push them back in) .... so start at the right rear wheel cylinder, with your assistant at the ready , attach the bleeder hose & open the bleeder screw just enough to allow fluid to escape, have your assistant press the brake pedal to the floor using gradual pressure once he reaches the floor with the pedal he should tell you this by simply calling out "floor" at that time tell him to "hold" meaning hold the pedal to the floor, then close the bleeder screw at which time you can tell him to "release" meaning to let the pedal return , repeat until no air is detected, then do exactly the same procedure at the left front ....with that you've bled the whole circuit. Recheck master cylinder level between bleedings to ensure you don't run dry as you'll have to start all over if you do and if you drain it completely and operate the brake pedal you'll be bleeding the entire system! This procedure is to be repeated if the pedal remains "spongy" once no air is detected at both ends you're done and hopefully your pedal has returned to normal and the brake warning light can be turned "off" (once the system is bled, topped up and closed with no leaks a good solid push on the brake pedal should turn it off, this resets the pressure differential valve in the fluid distribution block below the master cylinder). The K car system is small so the chance of air working its way into the circuit during the wheel cylinder change is very good as I've seen in the past. This way gets it all out and has always done the trick for me.
Not that I'm questioning your workmanship but double check the fitting connection at the cylinder prior to you starting the bleeding procedure. The above bleeding procedure is pretty well a standard way of doing it unless you have pressure bleeding equipment , the reverse system described to you would be ineffective. Have fun and good luck...let me know how it works out....

[jco1971136]

Thank you Kwagon. The Master Cylinder was bone dry when I got to my sisters house so I guess I will have to bleed them all, but I will try doing just the 2 first. Thanks again for all of your help, and I certainly will let you know what happens. I would like to reward you for your time but I am currently unemployed, but I do know quite a bit about computers and if you ever need any computer support, please don't hesitate to contact me.

Take care, and have a great holiday!

[jco1971136]

Kwagon - I tried again but the police told me I had to have it out of their lot by the next day. I arranged to borrow some money from a family member and a mechanic down the street took it in and they're supposed to work on it tomorrow (Friday). I wanted to thank you again for all of the great advice.

I have another question if you don't mind. I thought I would post another question on the board, but since I have your attention and you seem very knowledgeable, here goes.

I was working on my turn signals because they were blinking very slowly. I fixed that problem, by replacing one of the bulb sockets, but now the dome light is out and the radio doesn't work at all. Both worked in the past. I checked all of the fuses and they're fine. I don't think the light and radio are related to the work I done on the turn signals but there is a wire coming out of the negative battery cable connection, that goes nowhere. I was just wondering if this wire is extra, or if it should be attached to a ground or something else.

Thanks again for your time
Merry Christmas

[Kwagon2]

Hi
I hope those mechs got you all fixed up!! Hope you had a great Christmas!
That wire you're describing could be the body ground , there are two wires that come out of the negative battery post clamp, one goes to the engine near the air pump bracket that's a heavy one , the small one (about a #10AWG) is the body ground and if you look around the left fender shield you may find the other end, splice a chunk of wire in and re-attach it.
I have no firm answer with regards to the dome light or the radio, the dome light is fed from fuse 6 which feeds all of the auxillary lighting , trunk lamp, ignition switch lamp and the stop lamps! Stop lamps are tied to the same socket terminal as the turn signal as the turn signal filament is used for the stop light function when not selected through the turn signal switch so you could have something going on there.
The radio is fed from fuse 9 and 7 as the memory feed is hot all the time (fuse 7) , fuse 9 is energized when the ignition switch is in the "run" position or in the accessory position. That's all with the factory radio(s) I'd check all that stuff again , if you have a volt meter I'd do some voltage checks etc.
On your other post regarding the turn signal switches back in july I posted a few schematics ...they may be of some use again!
Take Care!

[jco1971136]

Hi Kwagon2 - Sorry it took so long to get back to you, I was doing other stuff to the car and it slipped my mind.
It turns out in my rushing to fix the lights problem, I (apparently) removed 2 fuses from the fuse box marked "auxiliary". I put a few 20 amp fuses in those places and everything worked, except the trunk light. Anyway, she's was back up and running, until last week, LOL.

I have another question, but I'm not sure if I should just ask you or create a new post. If I need a new post let me know and I'll do that, but here goes.
I had been getting code 15 (no vehicle speed signal - no distance sensor signal detected during road load conditions), since forever, but I was told it really didn't matter, so I just let it be. I started getting an 02 sensor code, (above or below center, I dont remember the exact error), but I read in the manual that it is possible to get an 02 problem code because there is a fuel pressure problem, so I tried to release the pressure using the method in the book, which said you could use 2 wires to relieve any risidual pressure, so I tried it, and it didn't work out so good because now I'm getting codes related to the charging system and the battery wont hold a charge. If I jump it, it runs fine, but if I let it sit overnight it wont start in the morning. The codes I'm getting now are:

#15 - No vehicle speed signal - no distance sensor signal detected during road load conditions (I know whats going on here, as I mentioned above).
#16 - Battery input sense - Battery voltage sense input not detected during engine running.
#46 - Charging system voltage too high - Battery voltage sense above target charging voltage during engine operation.

I'm thinking it's a Voltage Regulator problem, but how do I test that?

Oh, BTW, I started it and then disconnected the battery so I'm pretty sure the alternator is Ok.

Thanks again for all your help Kwagon2

Jim