1970 Olds 442 Developed Mushy Brakes(Power Front Disc)
#1
1970 Olds 442 Developed Mushy Brakes(Power Front Disc)
On the way to a show on Saturday after I stopped for breakfast I lost what is normally a pretty nice feeling pedal. I was close to the show so finished off the drive just allowing extra stopping distance. It wasn't feeling unsafe just went mushy. Parked it and walked around looking at cars while it cooled down a bit under the hood.
-Checked fluid and the front reservoir is low.
-Since front was low I inspected front calipers and inside wheels. No fluid
-Where the master meets the booster it is damp and looks like some fluid might have been dripping down there and the paint is bubbling slightly
So it sounds like I might have a leak inside the master that is leaking into the booster. At least from my experience this might be the case.
Anything else to check? And recommendation on where to buy these parts? And once acquired anything special to bleed this setup? None of my BMWs have bleeders on the resevoir/master. I'd just use a power bleed at the calipers and then do a couple manual activation per corner.
-Checked fluid and the front reservoir is low.
-Since front was low I inspected front calipers and inside wheels. No fluid
-Where the master meets the booster it is damp and looks like some fluid might have been dripping down there and the paint is bubbling slightly
So it sounds like I might have a leak inside the master that is leaking into the booster. At least from my experience this might be the case.
Anything else to check? And recommendation on where to buy these parts? And once acquired anything special to bleed this setup? None of my BMWs have bleeders on the resevoir/master. I'd just use a power bleed at the calipers and then do a couple manual activation per corner.
#2
On the way to a show on Saturday after I stopped for breakfast I lost what is normally a pretty nice feeling pedal. I was close to the show so finished off the drive just allowing extra stopping distance. It wasn't feeling unsafe just went mushy. Parked it and walked around looking at cars while it cooled down a bit under the hood.
-Checked fluid and the front reservoir is low.
-Since front was low I inspected front calipers and inside wheels. No fluid
-Where the master meets the booster it is damp and looks like some fluid might have been dripping down there and the paint is bubbling slightly
So it sounds like I might have a leak inside the master that is leaking into the booster. At least from my experience this might be the case.
Anything else to check? And recommendation on where to buy these parts? And once acquired anything special to bleed this setup? None of my BMWs have bleeders on the resevoir/master. I'd just use a power bleed at the calipers and then do a couple manual activation per corner.
-Checked fluid and the front reservoir is low.
-Since front was low I inspected front calipers and inside wheels. No fluid
-Where the master meets the booster it is damp and looks like some fluid might have been dripping down there and the paint is bubbling slightly
So it sounds like I might have a leak inside the master that is leaking into the booster. At least from my experience this might be the case.
Anything else to check? And recommendation on where to buy these parts? And once acquired anything special to bleed this setup? None of my BMWs have bleeders on the resevoir/master. I'd just use a power bleed at the calipers and then do a couple manual activation per corner.
#3
If the way you bleed brakes works fine disregard this suggestion. Came across a method called reverse bleeding if you want to consider trying. Good luck.
https://www.brakebleeder.com/solutio.../how-it-works/
https://www.brakebleeder.com/solutio.../how-it-works/
#4
If you suspect that brake fluid got in the booster I'd definitely pull it & check it. When I did the disc brake conversion on my '68 I was replacing the booster anyway but the old one had quite a bit of brake fluid in it. I don't think that brake fluid would hurt the rubber parts inside the booster but they're cheap enough I'd put a new one on along with the master.
#5
Again, the M/C has to be replaced no matter what. Once you pull it off, it will be obvious whether or not there is fluid leaking out the back. The seal between the M/C and booster should prevent fluid from being sucked into the booster. Usually there is a wet trail down the outside of the booster under the back of the M/C when this happens.
Check the condition of this seal when the M/C is off.
As for the reverse bleeder systems, why in the world would you want to push old brake fluid contaminated with worn seals back into your new master cylinder. I've never been able to understand why that system makes any sense.
Check the condition of this seal when the M/C is off.
As for the reverse bleeder systems, why in the world would you want to push old brake fluid contaminated with worn seals back into your new master cylinder. I've never been able to understand why that system makes any sense.
#6
Copy. That was my plan. I looked at prices and even the nicest/best ones are not too much. With the simple system replacing in the garage should be quite easy...
Now if only I owned a single standard tool. A long time of BMW ownership means I just have a lot of metric and a bunch of 10mm and 13mm as they go missing...
Now if only I owned a single standard tool. A long time of BMW ownership means I just have a lot of metric and a bunch of 10mm and 13mm as they go missing...
#7
Copy. That was my plan. I looked at prices and even the nicest/best ones are not too much. With the simple system replacing in the garage should be quite easy...
Now if only I owned a single standard tool. A long time of BMW ownership means I just have a lot of metric and a bunch of 10mm and 13mm as they go missing...
Now if only I owned a single standard tool. A long time of BMW ownership means I just have a lot of metric and a bunch of 10mm and 13mm as they go missing...
#9
The line wrenches Joe posted will certainly come in handy as you know . I spray the fittings with liquid wrench the day or two before I start wrenching on the brake lines, depending on corrosion. I hate twisting lines then having to replace them.
#10
Might as well flush the whole brake system while you're at it. Brake fluid absorbs moisture and causes rust, might be time to start fresh, the front hoses to the calipers can also deteriorate over time. Reverse bleeding works great, one man operation, best way to get rid of air.
#11
Might as well flush the whole brake system while you're at it. Brake fluid absorbs moisture and causes rust, might be time to start fresh, the front hoses to the calipers can also deteriorate over time. Reverse bleeding works great, one man operation, best way to get rid of air.
#12
Get chew one of these(see links). Quick...easy. I can do all 4 bleeders in 30 mins or less. Dont forget to get the correct master cylinder adapter. I see they have upgraded the pump hose with a quick-disconnect. Make sure the adapter comes with the mating male end. I have several adapters for each vehicle I own. I use small surgical hose(amazon) attached to the bleeders down into a cup to recover the waste fluid.
Always use the correct fluid. Make sure its fresh and of high quality. Never store the fluid in the motive pump. Store everything in a clean dry environment. Never use fluid thats been in an open container with fluctuating ambient conditions. It does absorb moisture just sitting in the container same for your brake system.
I bleed all of my vehicles brakes on a biennial or triennial basis regardless of miles. Thats why my 95 Jeep GC has its original calipers. Sure its soft lines have been replaced as those lines should be replaced every decade or so as a safety item.
How many people do this...only the few ****-retentives like myself..
Clean fresh fluid and clean tools equals a happy safe long lasting hydraulic brake system.
https://www.summitracing.com/parts/mvp-0106?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-motive-products&gclid=Cj0KCQjwiJncBRC1ARIsAOvG-a4tZFE0PcRCRzflW7kx2iOUF63_Zh9wfwlwyNogJ36dMwtkzEm aMggaAvW6EALw_wcB
https://www.jegs.com/i/Motive-Products/715/0090/10002/-1?CAWELAID=1710740688&CAGPSPN=pla&CAAGID=157690684 31&CATCI=pla-224363064311&CATARGETID=230006180037474793&cadevic e=c&jegspromo=thirdparty&gclid=Cj0KCQjwiJncBRC1ARI sAOvG-a54wAFrgRi9111uheX4JfEVwsRGwr2AwXihNYe20g32xjtsyES Yqw4aAp3fEALw_wcB
Always use the correct fluid. Make sure its fresh and of high quality. Never store the fluid in the motive pump. Store everything in a clean dry environment. Never use fluid thats been in an open container with fluctuating ambient conditions. It does absorb moisture just sitting in the container same for your brake system.
I bleed all of my vehicles brakes on a biennial or triennial basis regardless of miles. Thats why my 95 Jeep GC has its original calipers. Sure its soft lines have been replaced as those lines should be replaced every decade or so as a safety item.
How many people do this...only the few ****-retentives like myself..
Clean fresh fluid and clean tools equals a happy safe long lasting hydraulic brake system.
https://www.summitracing.com/parts/mvp-0106?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-motive-products&gclid=Cj0KCQjwiJncBRC1ARIsAOvG-a4tZFE0PcRCRzflW7kx2iOUF63_Zh9wfwlwyNogJ36dMwtkzEm aMggaAvW6EALw_wcB
https://www.jegs.com/i/Motive-Products/715/0090/10002/-1?CAWELAID=1710740688&CAGPSPN=pla&CAAGID=157690684 31&CATCI=pla-224363064311&CATARGETID=230006180037474793&cadevic e=c&jegspromo=thirdparty&gclid=Cj0KCQjwiJncBRC1ARI sAOvG-a54wAFrgRi9111uheX4JfEVwsRGwr2AwXihNYe20g32xjtsyES Yqw4aAp3fEALw_wcB
Last edited by droldsmorland; August 29th, 2018 at 02:11 PM.
#13
I actually prefer the Vacula bleeder, same idea but it uses shop air to create a vacuum. I've never had to bleed more than one time, nor do I even have to bench bleed the master cylinder. This just sucks all the air right out of the system. Best tool I've ever bought.
#15
#17
I actually prefer the Vacula bleeder, same idea but it uses shop air to create a vacuum. I've never had to bleed more than one time, nor do I even have to bench bleed the master cylinder. This just sucks all the air right out of the system. Best tool I've ever bought.
#18
Air that leaks around the bleeder threads immediately gets sucked into the unit. Yeah, the fluid coming from the screw into the bleeder unit has air bubbles from this. Who cares? The air flows to the lowest pressure area, which is inside the unit. It can't physically flow upstream into the brake system.
#20
I just run the bleeder until it sucks about 1/4 of the fluid out of the M/C reservoir, then go on to the next wheel. Probably more like 1/2 if the lines are empty or I want to completely flush the system. Actually, you can hear the difference in the sucking sound. The sound is different if there is a lot of air coming out vs. just the leakage around the bleeder screw.
#21
$15 bucks... , Oh, I bet you felt awful taking it off his hands for a steal eh haha!
#27
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