Bleeding Hydraulics

[Underdog]

They debate this subject about once a week on the MG website. I've never had a problem myself with either the clutch or brakes until yesterday. I use the two person method and with the aid of my lovely assistant, it always works fine.

Yesterday I was working on the TR8. Replaced the rotors, pads and new set of wheel brgs. So now it was time to bleed and just in time as Laurie got home.

I decided to do something a little different this time. I use DOT 5 and had read that pumping the pedal was not good as it can make air bubbles that take a while to come out of DOT5. Well I told her press the pedal down & opened the bleeder. After several atemps at this, all I was getting was a tiny drible. I went from side to side & same thing. Finnally, I said "the heck with this...go ahead & pump em up" Again, only a tiny dribble. Back & forth from side to side..nothing. I even left the far side bleeder open & told her go ahead & pump away...nothing.

I was begining to wonder if somehow the master had gone kaput. What's the chances though..I thought. Finally, after a good 15 minutes of this I said "jump out & let me try the pedal" I got in, gave a few pumps and could feel pressure build. She says " OMG I was doing the clutch!!! By this time I was too tired to chase her around the garage. She said something about a blond moment, we proceded to bleed them in about 5 minutes.

72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.

[busheytrader]

[:)]

[Marko]

hmmm, dot5 in a tr7? auch!

dont you mean dot 5.1 ??

[Underdog]

Silicone. Here it's called DOT 5

72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.

[Wayne S]

Hahaha [:D]

I use Dot 5.1 in both my cars.

Wayne

<b>2.0 Litre DHC Grinnall
Red 4.0 Litre V8 DHC Grinnall (with huuuuuge arches...!)</b>

[pupinabox]

[:D][:)][:D][:)][:D][:)][:D][xx(]

[jclay (RIP 2018)]

Saves time and gives you more energy to chase the baby's mother!



[url="http://www.speedbleeder.com/"]Speed Bleeders![/url]

jclay

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[Marko]

[quote]<i>Originally posted by Underdog</i>

Silicone. Here it's called DOT 5

72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

everywhere in the world dot5 is silicone based, but will the rubbers in the hydraulic system of the brakes survive the dot5 is another question. silicone swells natural rubber.

[Beans]

Have used DOT5 or silicon brake fluid in the past, will never ever use it again [B)]
Better to use a good quality DOT4 and regularly change it to get moisture and (worn)rubber bits out of the system.

<center>
<font color="blue"><i>1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (now completely dismantled)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC</font id="blue">
<font color="red">http://tr7beans.blogspot.com/</i></font id="red"></center>

[Underdog]

everywhere in the world dot5 is silicone based, but will the rubbers in the hydraulic system of the brakes survive the dot5 is another question. silicone swells natural rubber.

[/quote]

Another subject heavily debated on the MGB Forum. Have it in the MGB, TR8, Harley, Yamaha, Boat trailer and an 86 Chevy. Never had a problem in 17 yrs of useing it. Perhaps none of my applications have natural rubber? Does burn your eyes for some reason but doesn't suck up moisture and you can spill it all over the paintwork with no effect.[:D] The latter is the bigest reason I started using it. The boat trailer and old Chevy got it for corrosion resistance.

72 MGB BRG
80 TR8 Persian Aqua
If women don't find you handsome, they should at least find you handy.

[Beans]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Underdog</i>

...but doesn't suck up moisture ...<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
That's its biggest disadvantage, moisture will collect at the lowest point causing corrosion inside the calipers/cylinders.

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Underdog</i>

... you can spill it all over the paintwork with no effect ...<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
Have to admit that it is great for polishing the car's paintwork [:p]


<center>
<font color="blue"><i>1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (now completely dismantled)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC</font id="blue">
<font color="red">http://tr7beans.blogspot.com/</i></font id="red"></center>

[FI Spyder]

A friend uses it in his Spitfire with no ill effects. Their master cylinder sits on the horizontal bulkhead so it's a very good reason to use it. Talked to other users that are happy with it.

It was incompatible with rubber used when it was first introduced years ago but not the case now with todays rubber components.

Should only be used on systems that have been rebuilt so no old fluid soaked rubber is used.

The water collecting in the systems is often cited but unlike regular fluid silicone does not absorb water were would it come from. Not enough space in master cylinder for condensation to be a factor.

There is some air interspersed in the fluid molecularly so there is some compression to it but SS hoses should countereact that with a net negative result.

I chose not to use it because of the dreaded one rear bleed niple syndrome and I didn't feel like experimenting.

Apparently the US military like it because less maintenance is neccessary.

For bleeding I use a one way valve/container that plugs into bleed nipple I bought at Princess Auto for $5.00. Plug one end of hose into bleed nipple, open, container mounts anywhere with magnet. Pump away. I let it sit over night then get the wife to operate the regular way to get the last small bubbles out (looks like foam).

The silicone urban legends persist like aligators in the sewers or the cheap Corvette that had a dead body decomposed in it.[:)]



TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

[Marko]

both fluids will do their function the same ( even if 5.1 has slightly higher boiling point but most of the time you boil the water in the oil ,not the oil).

in my experience i try to stay away from the "less(low) maintenance" products because less maintenance always means corroded bolts and threads. in the brake caliper that means corroded bleed nipple and in most cases corroded bleed nipple means that it will brake , and i need to remove the whole caliper from the car to drill out the part that was left in.