89 sierra dummy lights

[anton!o]

just bought this 89 sierra SLE stepside reg cab, auto, pick up.... apparently it has 70,000km on the new motor, a newer tranny, 375,000km on the truck(odo) though.... new rad, alt, and starter... lol as soon as i bought it, i noticed that if i put over 40 bucks in gas it would start leakin like crazy outta the tank somewhere... also, when im drivin at high way speeds i notice when i let off the gas for even a second, the SES light comes on and as soon as i push the gas again the light goes off... also the e-brake light came on recently and it never goes off now...one more quick thing, how do i figure out what engine size i have, and wat size tank im goin to need to replace this one....also if u guys think i got ripped off, i payed 2800$CDN

[anton!o]

also, will a newer year grill and headlight assembly such as a 92-94 or something bolt right up to my 89

[fuzzypuppy]

I will address a couple of your issues/
1, leaking fuel, the problem could be that someone drilled a hole in the tank while installing something in the bed, "rollbar etc" I have seen this several times, check your bed for holes, it could also be one or more of the hoses has rotted and broken also the connections or seal at the fuel pump/sender.
2, The brake light, not only does this light indicate for the e-brake but it is the indicator for the "low brake fluid" sensor, check your brake fluid level, if the brake fluid is at the proper level the sensor may be bad.
3, SES light, If the light comes on a code has been set, retrieve the code by jumpering the two upper right terminals on the diagnostic block connector under the dash near the steering colum, after jumpering the two terminals turn the key to on but do not start, the SES light will flash in a series, the number of flashes indicates the number for a code with a pause between flashes such as, blink pause blink blink, this demonstration I just wrote would indicate a 12 code, 1blink pause 2blink = 12, each code will repeat 3 times.
First code will always be a 12 code, and the last code will always be a 12 code to let you know the diagnostic's display is complete, if you don't catch the codes it's ok because they will continue to repeat as long as the key is on with the 12 codes always first and last.
What you want to do is record the code or codes between the 12 codes, these codes will lead you in the direction of the fault. you can then try posting back here for help with these codes, most big name auto part stores can tell you what they mean or buy a haynes or chiltons repair manual that will contain an explination of all the codes possible along with the same instructions I just gave you.
As far as the grill, it should bolt up.