MGExp

MGB & GT Forum

Dash is off, now what?

Moss Motors
AutoShrine Sponsor
AutoShrine Sponsor
AutoShrine Sponsor
AutoShrine Sponsor

RichW Avatar
RichW Richard Wichman
Iola, Kansas, USA   USA
1972 MG MGB
Took the dash off the '72 roadster today. Wasn't nearly as bad a job as I thought it would be. I have no idea if any of the instruments work or not, though. I would like to get them checked out before the dash goes back. A lot easier to remove them now! Any recommendations on who could do this? For some reason the PO had disconnected the oil pressure line to the gauge at the engine and capped it. I am guessing it had a leak? Wish I knew why he did it before the dash goes back. What part is most likely to fail on the manual oil pressure gauge? Thanks.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <

Attachments:
IMG_1841.JPG    43.1 KB
IMG_1841.JPG

RAY 67 TOURER Avatar
RAY 67 TOURER Ray Marloff
Fort Bragg, CA, USA   USA
1967 MG MGB "My Girl"
The oil line, itself, is the most likely part to fail. There's a leather gasket at the back of the oil gauge. The gauge rarely gives any trouble. Nissongers is a great place to send your gauges to. RAY

tahoe36c Avatar
tahoe36c Paul Hruza
Panama City, FL, USA   USA
1969 MG MGC GT "Little Red Rocket..."
1972 MG MGB GT "Tiny Dancer"
2002 Harley-Davidson Dyna
I am confused as to why you didn't perform an operational of the gauges prior to removal... Is (was) the car operational?

Gauges can be ops checked. Even the speedo. You can spin the speedo with a drill. I did this when I was learning how to rest my odometer to zero.

I would not send them to pay someone for this. It is not difficult.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
GTgeezer Avatar
GTgeezer Lynn Kirkpatrick
Columbia City, Indiana, USA   USA
Rick Astley has published a book on MGB electricals. That explains the working of the entire car, including the gauges. I didn't have to test my gauges during the dash redo, because they all worked, but I think you could do the testing from reading his book. He also gives a lot of tips on maintaining the system.

I suggest you also look for the wiring diagrams, not just the schematics. The diagrams show how everything is connected. The schematics show how everything works. There is a difference. The diagrams will show you where to look if there is a problem. There is an e-copy of the MGB shop manual online. Sorry, I can't locate my copy to give you the title. Bentley also published one, if you prefer to look at paper, instead of the screen.
Good luck.



Don't confuse me with facts. I've already made up my mind.

RichW Avatar
RichW Richard Wichman
Iola, Kansas, USA   USA
1972 MG MGB
This car has not been operational for many, many years. I decided to just strip it clear down now, instead of rebuilding the whole fuel system and trying to get it running again first. I do know the trip reset on the speedo is frozen.

saanich2006 Avatar
saanich2006 Robert Browning
Atlanta, Georgia, USA   USA
Before you put the dash back in, paint the back of it bright white.

It sure makes it a lot easier later on when you are looking up under it trying to find a wire or something.

Ask me how I know!!



"He had delusions of adequacy."

Law of Mechanical Repair - After your hands become coated with grease, your nose will begin to itch and you'll have to pee.



tahoe36c Avatar
tahoe36c Paul Hruza
Panama City, FL, USA   USA
1969 MG MGC GT "Little Red Rocket..."
1972 MG MGB GT "Tiny Dancer"
2002 Harley-Davidson Dyna
Richard,

This will help with the Speedo....

. Hide banner ads & support this website by becoming a > Gold Supporting Member <

Attachments:
Smith's Speedo Repair.pdf    1.31 MB

BumbleB74 Avatar
BumbleB74 William Milholen
Tidewater, Tidewater VA, USA   USA
Rick Astley's book also talks about how to check the tachometer using a simple battery charger.

Aside from checking on things, you can easily take the trim rings off and polish them with some Semichrome or Flitz polish. You'll likely be amazed how well they can clean up! Clean the glass for each one, but do NOT think about cleaning the actual faces of the gauges. That paint is old and if you use the wrong chemical....you can mess them up.

A mechanical oil gauge can be checked easily if you have a small air compressor with a regulator. Just rig up a hose between the gauge and the air compressor. You can simply clamp a hose over the nipple on the back of the gauge, and slowly open the regulator on the air compressor and see how the needle responds. Don't be overly concerned if they don't jive exactly, but they should be close. Cycle the pressure up and down a few times between 0 and 75 psi to see how the needle swing. Should go up and down smoothly.



1974-1/2 Roadster, "Bumble Bee", Corvette Yellow - in shambles, wire wheels
1976 Roadster, "Virus", Sandglow - "driver" condition (stock + 32/36 Weber DGEV, cast iron header, 25D distributor), bolt on wheels, ON the road!

course2kid Jeffrey Johnson
Fountain Valley, CA, USA   USA
1979 MG MGB "Lucy (Lucifer)"
You can also test the temp and fuel gages easily. Just hook a wire from either gage terminal to the positive terminal of a car battery (or a 9V battery if that's easier) and connect the other terminal of the gage to the negative terminal of the battery. The gage needle should slowly swing from cold/empty to hot/full. Just to be safe, don't leave the gage connected to the 12V battery for very long.

This will check the basic functionality. If you want to clibrate the gages, you can do that with the car battery, the gage voltage stabilizer, and a couple resistors of 20 ohm and 220 ohm resistance. Just wire 12v to gage stabilizer, ground the body of the gage stabilizer to battery neg, and wire the gage and resistor in series from the gage stabilizer to battery neg. With the 20 ohm resistor the gage should read hot/full and with the 220 ohm resistor, it shoyld read cold/empty.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
. Hide banner ads & support this website by becoming a > Gold Supporting Member <

To add your reply, or post your own questions

Members Sign In   or   Create an Account

Registration is FREE and takes less than a minute!


Having trouble posting or changing forum settings?
Read the Forum Help (FAQ) or contact the webmaster